COLLABORATION AGREEMENT

Exhibit 10.19

[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

COLLABORATION AGREEMENT

This Collaboration Agreement (“ Agreement ”) is effective this 22nd day of March, 2005, by and between HOKU SCIENTIFIC, INC., a Delaware corporation located at 2153 North King Street, Suite 300, Honolulu, Hawaii 96819 USA (“ HOKU ”), and NISSAN MOTOR CO., LTD., located at 2 Takara-cho, Kanagawa-ku, Yokohama, Kanagawa 220-8623 Japan (“ NISSAN ” and, together with HOKU, the “ Parties ”).

BACKGROUND & PURPOSE

HOKU is developing HOKU Membrane and HOKU MEA (each as defined below) for use in proton exchange membrane fuel cells (“ PEMFC ”).

NISSAN develops and manufactures NISSAN Fuel Cells (as defined below).

HOKU and NISSAN are parties to that certain MEA Engineering Agreement dated as of September 1, 2004 (the “ Engineering Agreement ”) and that certain Membrane & MEA Purchase Agreement dated as of September 1, 2004 (the “ Purchase Agreement ”), pursuant to which HOKU optimized Automotive HOKU MEA and the Automotive HOKU MEA Assembly Process to meet NISSAN’s Step 1 Goals (as defined in the Engineering Agreement), and NISSAN purchased HOKU Membrane and HOKU MEA for test and evaluation.

Subject to the terms set forth herein, after further discussion by the Parties of the development plan for the Final MEA Product (as defined below) NISSAN desires HOKU to continue engineering customized HOKU MEA for use in automotive PEMFC, and to continue supplying HOKU Products for test and evaluation by NISSAN.

For good and valuable consideration, the receipt and adequacy of which is hereby acknowledged, the Parties agree as follows:

AGREEMENT

1. Definitions . The following terms shall be defined in this Agreement as set forth below:

1.1. “ Acquisition ” means the sale, conveyance or other disposal of all or substantially all of the assets or property of a Party, a merger with or into or consolidation of a Party into any other corporation, limited liability company or other entity (other than a wholly-owned subsidiary of such Party), or the merger of any other corporation, limited liability company or other entity into a Party, or any other corporate reorganization, sale, conveyance or other disposal of assets, consolidation, reorganization or merger, in which the shareholders of such Party receive distributions in cash or securities of another corporation, limited liability company or other entity as a result of such sale of assets, consolidation, reorganization or merger.

1.2. “ Agreement ” means this Collaboration Agreement.

1.3. “ Automotive HOKU MEA ” means the HOKU MEA that is developed by HOKU for use in automotive PEMFC, regardless of the date or source of development.

1.4. “ Automotive HOKU MEA Assembly Process ” means the HOKU MEA Assembly Process that is developed by HOKU to assemble the Automotive HOKU MEA, regardless of the date of development or source of development.

1.5. “ Background HOKU Technology ” means all technology developed by HOKU prior to the term of the Engineering Agreement.

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[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

1.6. “ Background NISSAN Technology ” means all technology developed by NISSAN prior to the term of the Engineering Agreement.

1.7. “ Catalyst ” means a Component that typically consists of precious metals and/or alloys, which helps to initiate and maintain the electrochemical reaction of fuel and oxidant that is needed to generate electricity in a PEMFC.

1.8. “ Catalyst Support ” means the Component used to support the Catalyst in a PEMFC.

1.9. “ CCM ” means Membrane coated on both sides with Catalyst.

1.10. “ Component ” means any and all components (including, but not limited to, Catalyst, Catalyst Support, Electrode, Membrane, Liquid Ionomer, GDL, binder and seal) incorporated into MEA.

1.11. “ Confidentiality Agreement ” has the meaning set forth in Section 2 below.

1.12. “ Electrode ” means the Component that is the combination of Catalyst and Catalyst Support, and which consists of an anode and cathode located on opposite sides of the Membrane in a PEMFC.

1.13. “ Engineering Agreement ” has the meaning set forth in the Background & Purpose of this Agreement.

1.14. “ Final MEA Product ” means the specific Automotive HOKU MEA (made up of a specific set of Components) that is developed by HOKU, with or without assistance from NISSAN, during the term of the Engineering Agreement and this Agreement (including any renewals or extensions thereof) using the Final MEA Product Assembly Process, and which is described with particularity in a written disclosure that is signed by both Parties prior to the termination or expiration of this Agreement.

1.15. “ Final MEA Product Assembly Process ” means the specific Automotive HOKU MEA Assembly Process that is developed by HOKU during the term of the Engineering Agreement and this Agreement (including any renewals or extensions thereof), to assemble the Final MEA Product. This excludes any assembly or manufacturing process of any HOKU Components incorporated into the Final MEA Product.

1.16. “ Final MEA Product Intellectual Property ” means all patents, trademarks and copyrights related to the Final MEA Product, excluding (i) any Intellectual Property related to the Final MEA Product Assembly Process, (ii) the HOKU Components incorporated into the Final MEA Product, and (iii) NISSAN Intellectual Property.

1.17. “ Full-scale HOKU Membrane ” means approximately 1,200cm ² of HOKU Membrane.

1.18. “ Full-scale Automotive HOKU MEA ” consists of Automotive HOKU MEA with Full-scale HOKU Membrane, an approximately 400 cm ² active Electrode area, and GDL.

1.19. “ GDL ” means the material used to diffuse the fuel and oxidant in a PEMFC.

1.20. “ HOKU ” means HOKU SCIENTIFIC, INC., a Delaware corporation.

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[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

1.21. “ HOKU Authorized Personnel ” means the Chief Executive Officer, Chief Technology Officer and Chief Scientist of HOKU.

1.22. “ HOKU Catalyst ” means any Catalyst, other than a NISSAN Catalyst, incorporated into any HOKU MEA.

1.23. “ HOKU Catalyst Support ” means any Catalyst Support, other than NISSAN Catalyst Support, incorporated into any HOKU MEA.

1.24. “ HOKU CCM ” means any CCM developed by HOKU at any time.

1.25. “ HOKU Component ” means any and all Components developed by HOKU at any time.

1.26. “ HOKU Electrode ” means any Electrode, other than a NISSAN Electrode, incorporated into any HOKU MEA.

1.27. “ HOKU Facility ” means any facility owned, occupied or leased by HOKU.

1.28. “ HOKU GDL ” means any GDL, other than NISSAN GDL, incorporated into any HOKU MEA.

1.29. “ HOKU Intellectual Property ” means all Intellectual Property now or hereafter developed, owned or licensed by HOKU that is related to Background HOKU Technology, any HOKU Component, HOKU Product, HOKU MEA Assembly Process, the Final MEA Product, Final MEA Product Assembly Process, Final MEA Product Intellectual Property and the Jointly Developed Technology, including, without limitation, the Automotive HOKU MEA Assembly Process and the Final MEA Product Assembly Process and all Intellectual Property that is developed in connection with the foregoing pursuant to or independent from this Agreement; provided, however, that HOKU Intellectual Property shall not include NISSAN Catalyst, NISSAN Catalyst Support, NISSAN Electrode, or NISSAN GDL that is used in the Automotive HOKU MEA or the Final MEA Product, except that any process to apply NISSAN Catalyst, NISSAN Catalyst Support, NISSAN Electrode, or NISSAN GDL to the Automotive HOKU MEA or the Final MEA Product, that is developed by HOKU during the term of the Engineering Agreement and this Agreement, shall be considered HOKU Intellectual Property.

1.30. “ HOKU Liquid Membrane ” means all formulations of Liquid Ionomer technology developed by HOKU at any time.

1.31. “ HOKU MEA ” means all MEA technology developed by HOKU at any time, including the Automotive HOKU MEA, whether or not patented by HOKU, and including, without limitation, all materials and subcomponents comprising such MEA and all processes used to assemble such MEA, including the Automotive HOKU MEA Assembly Process, regardless of the date of development or the source of development.

1.32. “ HOKU MEA Assembly Process ” means the process, techniques and know-how used to assemble a HOKU MEA, regardless of date of development or the source of development.

1.33. “ HOKU MEA Border ” means any material that is used in a HOKU MEA to provide a reinforcement of the HOKU Membrane around the outer edges of the Electrodes, and all processes used to apply such material to the HOKU MEA, regardless of the date of development or the source of development. “HOKU MEA Border” does not include the seal or gasket used in a 5-Layer MEA With Seal (as separately defined below).

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[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

1.34. “ HOKU Membrane ” means all Membrane and HOKU Liquid Membrane technology developed by HOKU at any time, whether or not patented by HOKU, including, without limitation, (i) all materials and processes used in the development and production of such Membrane and HOKU Liquid Membrane technologies; (ii) all solid polymer and Liquid Ionomer forms of such Membrane and HOKU Liquid Membrane technologies; (iii) all formulations of such Membrane and HOKU Liquid Membrane technologies, including monomer and polymer formulations; and (iv) all reinforcements adjacent to such Membrane technologies and the process or processes used to apply the reinforcement material to the Membrane, regardless of the date of development or the source of development.

1.35. “ HOKU Product ” means Automotive HOKU MEA, Final MEA Product, HOKU Catalyst, HOKU Catalyst Support, HOKU CCM, HOKU Components, HOKU Electrode, HOKU GDL, HOKU Liquid Membrane, HOKU MEA, HOKU MEA Border, HOKU Membrane, HOKU Seal, and the Jointly Developed Technology.

1.36. “ HOKU Seal ” means any seal or gasket in a HOKU MEA that is a 5-Layer MEA with Seal, regardless of the date of development or source of development.

1.37. “ Intellectual Property ” means (a) all inventions (whether patentable or unpatentable and whether or not reduced to practice), all improvements thereto, and all patents, patent applications and invention disclosures, together with all reissues, continuations, continuations-in-part, revisions, extensions, and reexaminations thereof; (b) all copyrightable works, all copyrights, and all applications, registrations, and renewals in connection therewith; (c) all trade secrets and confidential business information (including without limitation, ideas, research and development, know-how, formulas, compositions, prototypes, manufacturing and production processes and techniques, technical data, designs, drawings, bills of materials, specifications, customer and supplier lists, contracts, pricing and cost information, and business and marketing plans and proposals); (d) all computer software and firmware (including related data, routines and documentation) in any media, type of code and format; (e) all trademarks and service marks (whether registered or not); and (f) all other proprietary rights of the foregoing items (a) through (e) of this definition and derivatives thereof in whatever tangible or intangible form, medium or embodiments.

1.38. “ Joint Laboratory ” means a laboratory facility located within the HOKU Facilities that may include a single cell and limited short stack testing equipment, and which is used by NISSAN and/or HOKU to evaluate HOKU Membrane and Automotive HOKU MEA pursuant to this Agreement.

1.39. “ Jointly Developed Technology ” means all inventions conceived or reduced to practice during the term of the Engineering Agreement and this Agreement (including any extensions or renewals thereof) where the inventors include one or more employees of HOKU and one or more employees of NISSAN. All Jointly Developed Technology shall be documented by both a HOKU and NISSAN engineer in a joint lab book (labeled “Project Unity: Work Towards Jointly Developed Technology”) and signed and dated by both persons.

1.40. “ Liquid Ionomer ” means a liquid electrolyte substance that is used to combine the Catalyst on the Electrode with Membrane for use in PEMFC.

1.41. “ MEA ” means CCM, 5-Layer MEA and 5-Layer MEA With Seal.

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[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

1.42. “ 5-Layer MEA ” means a membrane electrode assembly for electrochemical devices such as fuel cells and electrolyzers, which consists of a Membrane, Liquid Ionomer, two Electrodes (anode and cathode), a Catalyst and Catalyst Support, and GDL.

1.43. “ 5-Layer MEA With Seal ” means a 5-Layer MEA with the addition of seals or gaskets.

1.44. “ Membrane ” means a solid polymer electrolyte used in PEMFC to separate two Electrodes (anode and cathode) and conduct protons to facilitate the electrochemical reaction that generates electricity from fuel and oxidant in a PEMFC.

1.45. “ NISSAN ” means NISSAN MOTOR CO., LTD., a Japanese corporation.

1.46. “ NISSAN Affiliates ” means NISSAN’s associated companies in which it controls, directly or indirectly, greater than fifty percent (50%) of the voting power.

1.47. “ NISSAN Catalyst ” means the Catalyst developed by NISSAN at any time.

1.48. “ NISSAN Catalyst Support ” means any Catalyst Support developed by NISSAN at any time.

1.49. “ NISSAN Electrode ” means any Electrode developed by NISSAN at any time.

1.50. “ NISSAN Facility ” means a facility owned, operated or leased exclusively by NISSAN.

1.51. “ NISSAN Fuel Cells ” means PEMFC stacks, integrated systems and balance of plant developed by NISSAN at any time, for use in trucks and passenger vehicles produced by NISSAN, NISSAN Affiliates or RENAULT.

1.52. “ NISSAN GDL ” means the GDL developed by NISSAN at any time.

1.53. “ NISSAN Intellectual Property ” means all Intellectual Property developed, owned or licensed by NISSAN that is related to Background NISSAN Technology, the NISSAN Fuel Cells, NISSAN Catalyst, NISSAN Catalyst Support, NISSAN Electrode, NISSAN GDL, and NISSAN MEA and any other Components developed by NISSAN at any time; provided, however, that under no circumstances shall NISSAN Intellectual Property include any HOKU Intellectual Property.

1.54. “ NISSAN MEA ” means all MEA technology developed solely by NISSAN or by NISSAN and a third party other than HOKU, whether or not patented by NISSAN, and including, without limitation, all materials and Components comprising such MEA.

1.55. “ PEMFC ” means proton exchange membrane fuel cells.

1.56. “ Purchase Agreement ” has the meaning set forth in the Background & Purpose of this Agreement.

1.57. “ RENAULT ” means RENAULT s.a.s., a corporation duly incorporated and existing under the laws of France and having its head office at 13/15 Quai Alphonse Le Gallo 92513 Boulogne-billancourt, France.

1.58. “ Step 1 Goals ” has the meaning set forth in the Engineering Agreement.

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[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

1.59. “ Step 2 Goals ” means all of the goals identified in the columns labeled “Step 2 Goals” on Exhibit A attached hereto; provided, however, that the numeric values in the column titled “Step 2 Goals” are tentative and may be modified by mutual written agreement between the Parties.

1.60. “ Step 2 Targets ” means all of the targets identified in the columns labeled “Step 2 Targets” on Exhibit A attached hereto; provided, however, that the numeric values in the column titled “Step 2 Targets” are tentative and may be modified by mutual written agreement between the Parties.

1.61. “ Step 2 Cross-check Goals ” means all of the goals identified in the table labeled “Step 2 Cross-check Goals and Dates” on Exhibit B attached hereto.

1.62. “ Step Completion Verification ” means the form to be signed by each Party pursuant to Section 4.3 below, in substantially the form of Exhibit C attached hereto.

1.63. “ Sub-scale HOKU Membrane ” is [ * ] of HOKU Membrane.

1.64. “ Sub-scale HOKU CCM ” consists of Sub-scale HOKU Membrane coated on each side with [ * ] of Catalyst.

1.65. “ Sub-scale Automotive HOKU MEA ” consists of Automotive HOKU MEA with Sub-scale HOKU Membrane, a [ * ] active Electrode area, and GDL.

2. Confidentiality; Extension of Confidentiality Agreement Term .

2.1. Without limiting the terms of the Mutual Confidentiality Agreement (the “ Confidentiality Agreement ”) dated January 15, 2004, by and between the Parties, the terms of this Agreement and all information and materials disclosed by the Parties pursuant to this Agreement shall be deemed Confidential Information as defined in the Confidentiality Agreement, except for the permitted disclosures set forth in Section 10 below. By execution of this Agreement, the Parties agree to extend the term of the Confidentiality Agreement until the expiration or termination of this Agreement; provided, however, that each Party’s obligations to protect the confidentiality of any information disclosed prior to termination shall continue for a period of five (5) years after such expiration or termination.

2.2. Notwithstanding Section 2.1 above, NISSAN may disclose Confidential Information as defined in the Confidentiality Agreement to NISSAN Affiliates and RENAULT; provided, however, that (i) NISSAN shall disclose to HOKU the names of all such NISSAN Affiliates that have received Confidential Information, (ii) NISSAN shall impose on NISSAN Affiliates and RENAULT the same confidentiality obligations as NISSAN owes herein and pursuant to the Confidentiality Agreement, and (iii) NISSAN shall be liable for any breach of the terms of the Confidentiality Agreement by RENAULT or the NISSAN Affiliates.

3. Completion of Step 1 Goals . The Parties hereby acknowledge and agree that the Step 1 Goals have been substantially completed to the mutual satisfaction of the Parties.

4. Scope of Work . HOKU agrees to further optimize Automotive HOKU MEA and Automotive HOKU MEA Assembly Process for integration into the NISSAN Fuel Cells.

4.1. Location of Work . All work related to this Agreement shall be performed at HOKU’S facility in Hawaii, or at another location that is mutually agreed in writing by the Parties. NISSAN shall have the option, at its cost, to locate one of its employees in the Joint Laboratory on a full or part-time basis during the term of this Agreement for the sole purpose of evaluating Automotive

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[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

HOKU MEA in single cells to verify the progress that HOKU is making towards the Step 2 Targets. HOKU shall have no obligation to disclose to such NISSAN employee any HOKU Intellectual Property. Any such NISSAN employee shall have unrestricted access to the Joint Laboratory from 9:00 a.m. until 6:00 p.m., Monday through Friday, but shall not be permitted to enter any other laboratory or research facility within the HOKU Facility unless accompanied by one of the HOKU Authorized Personnel.

4.2. Work Timing . Work related to this Agreement shall occur between April 1, 2005 and December 31, 2005.

4.3. Step Completion Verification . NISSAN shall begin evaluating the completion of the Step 2 Cross-check Goals on the applicable “Start Date” date set forth on Exhibit B . Upon the substantial completion of the Step 2 Cross-check Goals NISSAN and HOKU shall each countersign the Step Completion Verification. The Parties anticipate that the Step Completion Verification for the Step 2 Cross-check Goals shall be signed (if at all) by January 31, 2006. Provided that the applicable Step 2 Cross-check Goals have been substantially satisfied, neither Party may unreasonably refuse to execute the Step Completion Verification by the date set forth in the previous sentence.

5. Intellectual Property .

5.1. Exclusive Ownership .

5.1.1. Except as specifically set forth in Sections 5.3, 5.4.2 and 11.3.1, as between the Parties, HOKU has the exclusive worldwide ownership and rights with respect to all HOKU Intellectual Property, regardless of the date of development or the source of development.

5.1.2. Except as expressly set forth herein, as between the Parties, NISSAN has the exclusive worldwide ownership and rights with respect to all NISSAN Intellectual Property, regardless of the date of development or the source of development.

5.2. No Transfer of Rights .

5.2.1. Except as specifically set forth in Sections 5.3, 5.4.2 and 11.3.1, no rights are granted to NISSAN with respect to HOKU Intellectual Property, regardless of the date of development or the source of development.

5.2.2. Except as specifically set forth herein, no rights are granted to HOKU with respect to NISSAN Intellectual Property, regardless of the date of development or the source of development.

5.3. Licenses . The Parties acknowledge that no determination has been made at this time regarding which of the two Parties will be responsible for manufacturing the Final MEA Product using the Final MEA Product Assembly Process for NISSAN Fuel Cells after the completion of the Step 2 Cross-check Goals. As such, the Parties hereby agree that following (i) the successful completion of the Step 2 Cross-check Goals evidenced by the execution by HOKU and NISSAN of the Step Completion Verification, and (ii) each Party’s substantial satisfaction of its respective obligations under this Agreement (including any amendments hereof), including, without limitation, all payment obligations set forth in Section 9, then:

5.3.1. HOKU will grant to NISSAN, NISSAN Affiliates and RENAULT a non-exclusive, non-transferable, royalty-free, fully-paid, worldwide license, without the right to grant any sublicense, to use, sell as part of a vehicle, make, or have made the Final MEA Product; provided,

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[ * ] = CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY BRACKETS, HAS BEEN OMITTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

however, that (1) the foregoing license may only be used by NISSAN, NISSAN Affiliates and RENAULT to make or have made the Final MEA Product that incorporates HOKU Membrane purchased from HOKU or its authorized agent/distributor, and (2) NISSAN, NISSAN Affiliates and RENAULT may use a subcontractor for the purpose of having such product made by such subcontractor only after receiving written permission from HOKU to do so.

5.3.2. HOKU will grant to NISSAN, NISSAN Affiliates and RENAULT a non-exclusive, non-transferable, royalty-free, fully-paid, worldwide license, without the right to grant any sublicense, to the Final MEA Product Assembly Process; provided, however, that (1) the foregoing license may only be used by NISSAN, NISSAN Affiliates and RENAULT to make or have made the Final MEA Product that incorporates HOKU Membrane purchased from HOKU or its authorized agent/distributor; (2) the foregoing license only applies to the Final MEA Product Assembly Process, and shall not include any improvements, permutations or changes made thereto, and (3) NISSAN, NISSAN Affiliates and RENAULT may use a subcontractor for the purpose of having the Final MEA Product made by such subcontractor only after receiving written permission from HOKU to do so. The foregoing license shall not be construed to grant any right to NISSAN, NISSAN Affiliates, and RENAULT to make or manufacture MEA (including, without limitation Final MEA Product) using the Final MEA Product Assembly Process for resale of MEA itself to any third party except for resale of such MEA as repair parts for the vehicles of NISSAN, NISSAN Affiliates or RENAULT.

5.3.3. The granting of any license associated with this Agreement shall include disclosure of any and all information and granting of Background Hoku Technology (if necessary), known by HOKU at the time the license is granted, required for NISSAN to make Final MEA Product using the Final MEA Product Assembly Process; provided, however, that HOKU shall not be required to disclose any information regarding the materials o