Mizuho discloses 9% StoneBridge Acquisition II stake (APAC)

Rhea-AI Filing Summary

Mizuho Financial Group, Inc. has disclosed a sizeable ownership position in StoneBridge Acquisition II Corporation. The firm reports beneficial ownership of 552,055 common shares, representing 9.0% of the class, with sole voting and sole dispositive power over all of these shares.

Mizuho, a Japan-based parent holding company, may be deemed an indirect beneficial owner of shares held directly by its wholly owned subsidiary, Mizuho Securities USA LLC. The shares were acquired and are held in the ordinary course of business and not for the purpose of changing or influencing control of StoneBridge Acquisition II Corporation.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

StoneBridge Acquisition II Corporation

(Name of Issuer)

Common Shares

(Title of Class of Securities)

G85096124

(CUSIP Number)

12/31/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. G85096124

1

Names of Reporting Persons

Mizuho Financial Group, Inc.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

JAPAN

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 552,055.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 552,055.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

552,055.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

9.0 %

12

Type of Reporting Person (See Instructions)

FI

Comment for Type of Reporting Person: Mizuho Financial Group, Inc., Mizuho Bank, Ltd. and Mizuho Americas LLC may be deemed to be indirect beneficial owners of said equity securities directly held by Mizuho Securities USA LLC which is their wholly-owned subsidiary.

SCHEDULE 13G

Item 1.
(a)	Name of issuer: StoneBridge Acquisition II Corporation
(b)	Address of issuer's principal executive offices: One World Trade Center, Suite 8500, New York, NY 10007
Item 2.
(a)	Name of person filing: Mizuho Financial Group, Inc.
(b)	Address or principal business office or, if none, residence: 1-5-5, Otemachi, Chiyoda-ku, Tokyo, 100-8176, Japan
(c)	Citizenship: Japan
(d)	Title of class of securities: Common Shares
(e)	CUSIP No.: G85096124
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
	Parent Holding Company
Item 4.	Ownership
(a)	Amount beneficially owned: 552,055
(b)	Percent of class: 9.0 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 552,055
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 552,055
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary. See Exhibit A
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. By signing below I certify that, to the best of my knowledge and belief, the foreign regulatory scheme applicable to Parent Holding Company is substantially comparable to the regulatory scheme applicable to the functionally equivalent U.S. institution(s). I also undertake to furnish to the Commission staff, upon request, information that would otherwise be disclosed in a Schedule 13D.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Mizuho Financial Group, Inc.

Signature:	/s/ Takahiro Katsura
Name/Title:	Takahiro Katsura, Managing Director, Global Corporate Function Coordination Department
Date:	02/12/2026

FAQ

How many StoneBridge Acquisition II (APAC) shares does Mizuho own?

Mizuho Financial Group reports beneficial ownership of 552,055 StoneBridge Acquisition II common shares. This holding gives Mizuho a 9.0% stake in the class, with sole voting and sole dispositive power over all reported shares.

What percentage of StoneBridge Acquisition II (APAC) does Mizuho control?

Mizuho Financial Group reports owning 9.0% of StoneBridge Acquisition II’s common shares. This level of ownership requires a Schedule 13G filing, reflecting a significant but non-controlling stake under U.S. securities ownership disclosure rules.

Does Mizuho seek control of StoneBridge Acquisition II (APAC)?

Mizuho states the securities were acquired and are held in the ordinary course of business, not to change or influence control. The filing explicitly disclaims any purpose or effect of influencing control of StoneBridge Acquisition II Corporation.

Who is the reporting person for the StoneBridge Acquisition II (APAC) 13G filing?

The reporting person is Mizuho Financial Group, Inc., a Japan-based parent holding company. It may be deemed to indirectly own the shares, which are directly held by its wholly owned subsidiary, Mizuho Securities USA LLC.

What voting power does Mizuho have over StoneBridge Acquisition II (APAC) shares?

Mizuho reports sole voting power over 552,055 StoneBridge Acquisition II common shares. It also reports sole dispositive power over the same number, with no shared voting or shared dispositive power indicated in the Schedule 13G.

When was Mizuho’s StoneBridge Acquisition II (APAC) position measured?

The Schedule 13G lists 12/31/2025 as the date of the reportable event. As of that date, Mizuho’s beneficial ownership was 552,055 common shares, representing 9.0% of the outstanding class according to the filing.