Exhibit 4.15



LOCK-UP AGREEMENT



THIS LOCK-UP AGREEMENT (this
“Agreement”) is dated as of February 29, 2024, by and between the undersigned (the “Holder”)
Arisz Acquisition Corp., a Delaware corporation (“Arisz” or “Parent”). Capitalized
terms used and not otherwise defined herein shall have the meanings given such terms in the Merger Agreement (as defined below).



BACKGROUND



A. On January 21, 2022, Arisz
entered into that certain Agreement and Plan of Merger (as amended as of April 4, 2022, October 10, 2022, April 24, 2023, July 28, 2023
and as may be further amended, supplemented or otherwise modified from time to time, the “Merger Agreement”),
by and between Arisz and Finfront Holding Company, a Cayman Islands exempted company (the “Company”), pursuant
to which (a) Arisz agreed to form BitFuFu Inc., a Cayman Islands exempted company, as its wholly owned subsidiary (“Purchaser”
or “PubCo”), (b) Purchaser would form Boundary Holding Company, a Cayman Islands exempted company, as its wholly
owned subsidiary (“Merger Sub”), (c) Arisz will be merged with and into Purchaser (the “Redomestication
Merger”), with Purchaser surviving the Redomestication Merger, and (d) Merger Sub will be merged with and into the Company
(the “Acquisition Merger”), with the Company surviving the Acquisition Merger as a direct, wholly owned subsidiary
of Purchaser (collectively, the “Business Combination”). Following the Business Combination, Purchaser will
be a publicly traded company listed on a stock exchange in the United States.



B. On February 16, 2022 and
February 22, 2022, respectively, each of PubCo and Merger Sub was incorporated under the laws of the Cayman Islands as an exempted company.
On April 4, 2022, each of PubCo and Merger Sub executed a joinder agreement along with Arisz and BitFuFu, agreeing to be bound by the
Merger Agreement as if such parties were parties thereto on the date of its signing.



C. On December 20, 2023, each
of PubCo and Merger Sub executed a supplemental joinder agreement along with Arisz and BitFuFu, agreeing to be bound by Amendment No.
2 to the Merger Agreement, Amendment No. 3 to the Merger Agreement and Amendment No. 4 to the Merger Agreement as if such parties were
parties thereto on the date of their signing.



D. The Holder is the record
and/or beneficial owner of certain Company Ordinary Shares, which will be exchanged for Purchaser Ordinary Shares pursuant to the Merger
Agreement.



E. As a condition of, and
as a material inducement for Parent to enter into and consummate the transactions contemplated by the Merger Agreement, the Holder has
agreed to execute and deliver this Agreement.



NOW, THEREFORE, for and in
consideration of the mutual covenants and agreements set forth herein, and other good and valuable consideration, the receipt and sufficiency
of which is hereby acknowledged, the parties, intending to be legally bound, agree as follows:



AGREEMENT



1. Lock-Up.



(a) During the Lock-up Period
(as defined below), the Holder irrevocably agrees that it will not offer, sell, contract to sell, pledge or otherwise dispose of, directly
or indirectly, any of the Lock-up Shares (as defined below), enter into a transaction that would have the same effect, or enter into any
swap, hedge or other arrangement that transfers, in whole or in part, any of the economic consequences of ownership of such Lock-up Shares,
whether any of these transactions are to be settled by delivery of any such Lock-up Shares, in cash or otherwise, publicly disclose the
intention to make any offer, sale, pledge or disposition, or to enter into any transaction, swap, hedge or other arrangement, or engage
in any Short Sales (as defined below) with respect to any security of the Purchaser.



(b) In furtherance of the foregoing,
the Purchaser will (i) place an irrevocable stop order on all Lock-up Shares, including those which may be covered by a registration statement,
and (ii) notify the Purchaser’s transfer agent in writing of the stop order and the restrictions on such Lock-up Shares under this
Agreement and direct the Purchaser’s transfer agent not to process any attempts by the Holder to resell or transfer any Lock-up
Shares, except in compliance with this Agreement.













(c) For purposes hereof, “Short
Sales” include, without limitation, all “short sales” as defined in Rule 200 promulgated under Regulation SHO under
the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and all types of direct and indirect stock pledges,
forward sale contracts, options, puts, calls, swaps and similar arrangements (including on a total return basis), and sales and other
transactions through non-US broker dealers or foreign regulated brokers.



(d) For purpose of this Agreement,
the “Lock-up Period” means with respect to the Lock-up Shares, the period commencing on the Closing Date and ending
on the date that is six (6) months thereafter.



The restrictions set forth herein
shall not apply to: (1) transfers or distributions to the Holder’s current or former general or limited partners, managers or members,
stockholders, other equity holders or direct or indirect affiliates (within the meaning of Rule 405 under the Securities Act of 1933,
as amended) or to the estates of any of the foregoing; (2) transfers by bona fide gift to a member of the Holder’s immediate family
or to a trust, the beneficiary of which is the Holder or a member of the Holder’s immediate family for estate planning purposes;
(3) by virtue of the laws of descent and distribution upon death of the Holder; or (4) pursuant to a qualified domestic relations order,
in each case where such transferee agrees to be bound by the terms of this Agreement.



In addition, after the Closing
Date, if there is a Change of Control, then upon the consummation of such Change of Control, all Lock-up Shares shall be released from
the restrictions contained herein. A “Change of Control” means: (a) the sale of all or substantially all of the consolidated
assets of the Purchaser and the Purchaser’s subsidiaries to a third-party purchaser; (b) a sale resulting in no less than a majority
of the voting power of the Purchaser being held by person that did not own a majority of the voting power prior to such sale; or (c) a
merger, consolidation, recapitalization or reorganization of the Purchaser with or into a third-party purchaser that results in the inability
of the pre-transaction equity holders to designate or elect a majority of the board of directors (or its equivalent) of the resulting
entity or its parent company.



2. Representations and
Warranties. Each of the parties hereto, by their respective execution and delivery of this Agreement, hereby represents and warrants
to the others and to all third party beneficiaries of this Agreement that (a) such party has the full right, capacity and authority to
enter into, deliver and perform its respective obligations under this Agreement, (b) this Agreement has been duly executed and delivered
by such party and is the binding and enforceable obligation of such party, enforceable against such party in accordance with the terms
of this Agreement, and (c) the execution, delivery and performance of such party’s obligations under this Agreement will not conflict
with or breach the terms of any other agreement, contract, commitment or understanding to which such party is a party or to which the
assets or securities of such party are bound.



3. Beneficial Ownership.
The Holder hereby represents and warrants that it does not beneficially own, directly or through its nominees (as determined in accordance
with Section 13(d) of the Exchange Act, and the rules and regulations promulgated thereunder), any Purchaser Ordinary Shares, or any economic
interest in or derivative of such stock, other than those securities specified on the signature page hereto. For purposes of this Agreement,
the Company Ordinary Shares beneficially owned by the Holder as specified on the signature page hereto, and the Purchaser Ordinary Shares
that such Company Ordinary Shares will be converted into pursuant to the Merger Agreement, are collectively referred to as the “Lock-up
Shares.”



4. No Additional Fees/Payment.
Other than the consideration specifically referenced herein, the parties hereto agree that no fee, payment or additional consideration
in any form has been or will be paid to the Holder in connection with this Agreement.



5. Termination of the Merger
Agreement. This Agreement shall be binding upon the Holder upon the Holder’s execution and delivery of this Agreement, but this
Agreement shall only become effective upon the Closing. Notwithstanding anything to the contrary contained herein, in the event that the
Merger Agreement is terminated in accordance with its terms prior to the Closing, this Agreement shall automatically terminate and become
null and void, and the parties shall not have any rights or obligation hereunder.





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6. Notices. Any notices
required or permitted to be sent hereunder shall be sent in writing, addressed as specified below, and shall be deemed given: (a) if by
hand or recognized courier service, by 4:00 PM on a business day, addressee’s day and time, on the date of delivery, and otherwise
on the first business day after such delivery; (b) if by fax or email, on the date that transmission is confirmed electronically, if by
4:00 PM on a business day, addressee’s day and time, and otherwise on the first business day after the date of such confirmation;
or (c) five days after mailing by certified or registered mail, return receipt requested. Notices shall be addressed to the respective
parties as follows (excluding telephone numbers, which are for convenience only), or to such other address as a party shall specify to
the others in accordance with these notice provisions:



| | (a) | If to Parent, to:
| | --- | -----------------

Arisz Acquisition Corp.

c/o MSQ Ventures

12 East 49th Street, 17th Floor

New York, NY 10017Attention: Fang
Hindle-Yang

Email: hindleyang@msqventures.com



with a copy to (which
shall not constitute notice):

Loeb & Loeb

345 Park Avenue, 19th
Floor

New York, NY 10154

Attention: Mitchell
S. Nussbaum, Esq.

E-mail: mnussbaum@loeb.com



| | (b) | If to the Holder, to the address set forth
on the Holder’s signature page hereto
| | --- | --------------------------------------------------------------------------------



with a copy to (which
shall not constitute notice):

Wilson Sonsini Goodrich
& Rosati

Professional Corporation

Unit 2901, 29F, Tower
C, Beijing Yintai Centre

No. 2 Jianguomenwai
Avenue

Chaoyang District,
Beijing 100022

The People’s
Republic of China

Attention: Dan Ouyang,
Esq./Ke Li, Esq.

Email: douyang@wsgr.com/keli@wsgr.com



or to such other address as any party may have
furnished to the others in writing in accordance herewith.



7. Enumeration and Headings.
The enumeration and headings contained in this Agreement are for convenience of reference only and shall not control or affect the meaning
or construction of any of the provisions of this Agreement.



8. Counterparts. This
Agreement may be executed in facsimile and in any number of counterparts, each of which when so executed and delivered shall be deemed
an original, but all of which shall together constitute one and the same agreement.



9. Successors and Assigns.
This Agreement and the terms, covenants, provisions and conditions hereof shall be binding upon, and shall inure to the benefit of, the
respective heirs, successors and assigns of the parties hereto. The Holder hereby acknowledges and agrees that this Agreement is entered
into for the benefit of and is enforceable by Parent and its successors and assigns.





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10. Severability. If
any provision of this Agreement is held to be invalid or unenforceable for any reason, such provision will be conformed to prevailing
law rather than voided, if possible, in order to achieve the intent of the parties and, in any event, the remaining provisions of this
Agreement shall remain in full force and effect and shall be binding upon the parties hereto.



11. Amendment. This
Agreement may be amended or modified by written agreement executed by each of the parties hereto.



12. Further Assurances.
Each party shall do and perform, or cause to be done and performed, all such further acts and things, and shall execute and deliver all
such other agreements, certificates, instruments and documents, as any other party may reasonably request in order to carry out the intent
and accomplish the purposes of this Agreement and the consummation of the transactions contemplated hereby.



13. No Strict Construction.
The language used in this Agreement will be deemed to be the language chosen by the parties to express their mutual intent, and no rules
of strict construction will be applied against any party.



14. Governing Law.
The terms and provisions of this Agreement shall be construed in accordance with the laws of the State of New York.



15. Controlling Agreement.
To the extent the terms of this Agreement (as amended, supplemented, restated or otherwise modified from time to time) directly conflicts
with a provision in the Merger Agreement, the terms of this Agreement shall control.



[Signature Page Follows]





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IN WITNESS WHEREOF, the parties hereto have caused this Lock-up Agreement
to be duly executed by their respective authorized signatories as of the date first indicated above.



| | ARISZ
    ACQUISITION CORP.
| | ---------------------------
| |                            
| | By:                        
| |                            
| |                            



[Signature Page to Lock-up Agreement]













IN WITNESS WHEREOF, the parties hereto have caused this Lock-up Agreement
to be duly executed by their respective authorized signatories as of the date first indicated above.



| | [NAME OF HOLDER]                               
| | -----------------------------------------------
| |                                                
| | By:                                            
| |                                                
| |                                                
| |                                                
| | NUMBER OF LOCK-UP SHARES: -[                  ]



[Signature page to Lock-up Agreement]