SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 6)

FiEE, Inc.

(Name of Issuer)

Common Stock, $0.01 par value

(Title of Class of Securities)

60365W102

(CUSIP Number)

Cao Yu
Room 802, Building 47, Rongcheng Garden, Xiangcheng District,
Suzhou City, F4, 215100
86 152 5004 8607

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

04/30/2026

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. Checkbox not checked

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP Number(s):

60365W102

Name of reporting person

Cao Yu

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

CHINA

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 4,615,012.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 3,568,371.00
10	Shared Dispositive Power 0.00

Aggregate amount beneficially owned by each reporting person

4,615,012.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

40.6 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person:

Note to Rows 7 and 11: The above-referenced shares of common stock, $0.01 par value per share (the "Common Stock"), of FiEE, Inc. (the "Issuer") beneficially owned by Cao Yu consist of (i) 1,604,166 shares of Common Stock issuable upon conversion of 1,145,833 shares of Series A Convertible Preferred Stock, $0.001 par value per share (the "Series A Convertible Preferred Stock"), which are convertible into shares of Common Stock at a ratio of 1.4 shares of Common Stock for each share of Series A Convertible Preferred Stock (the "Ratio"), (ii) 1,425,480 shares of Common Stock issuable upon the exercise of warrants to purchase Common Stock, and (iii) 1,585,366 shares of Common Stock. The shares of Series A Convertible Preferred Stock vote on an as-converted basis without regard to the Preferred Blocker (as defined below). Note to Row 9: The above-referenced shares of Common Stock beneficially owned by Cao Yu consist of (i) 557,525 shares of Common Stock issuable upon conversion of Series A Convertible Preferred Stock per the Ratio, (ii) 1,425,480 shares of Common Stock issuable upon the exercise of warrants to purchase Common Stock, and (iii) 1,585,366 shares of Common Stock. The shares of Series A Convertible Preferred Stock are not convertible into more than 19.99% of the number of shares of Common Stock outstanding immediately prior to the original issuance date of the Series A Convertible Preferred Stock (the "Preferred Blocker"); therefore, the Series A Convertible Preferred Stock cannot, in the aggregate, convert into more than 557,525 shares of Common Stock. Note to Row 13: The percentages reported in this Amendment No. 6 to the Schedule 13D ("Amendment No. 6") are based on 11,358,244 shares of Common Stock deemed outstanding pursuant to Rule 13d-3(d)(1) ("Rule 13d-3(d)(1)") of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), calculated as the sum of 8,328,598 shares of Common Stock outstanding as of April 27, 2026 according to records of the Issuer, plus (i) 1,604,166 shares of Common Stock that are issuable upon conversion of the Series A Convertible Preferred Stock beneficially owned by Cao Yu and (ii) 1,425,480 shares of Common Stock that are issuable upon the exercise of warrants to purchase Common Stock beneficially owned by Cao Yu.

SCHEDULE 13D

CUSIP Number(s):

60365W102

Name of reporting person

Hu Bin

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

GERMANY

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 3,125,745.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 2,480,224.00
10	Shared Dispositive Power 0.00

Aggregate amount beneficially owned by each reporting person

3,125,745.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

29.5 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person:

Note to Rows 7 and 11: The above-referenced shares of Common Stock beneficially owned by Hu Bin consist of (i) 1,203,046 shares of Common Stock issuable upon conversion of 859,319 shares of Series A Convertible Preferred Stock, which are convertible into shares of Common Stock per the Ratio, (ii) 1,069,040 shares of Common Stock issuable upon the exercise of warrants to purchase Common Stock, and (iii) 853,659 shares of Common Stock. The shares of Series A Convertible Preferred Stock vote on an as-converted basis without regard to the Preferred Blocker. Note to Row 9: The above-referenced shares of Common Stock beneficially owned by Hu Bin consist of (i) 557,525 shares of Common Stock issuable upon conversion of Series A Convertible Preferred Stock, (ii) 1,069,040 shares of Common Stock issuable upon the exercise of warrants to purchase Common Stock, and (iii) 853,659 shares of Common Stock. The shares of Series A Convertible Preferred Stock are subject to the Preferred Blocker; therefore, the Series A Convertible Preferred Stock cannot, in the aggregate, convert into more than 557,525 shares of Common Stock. Note to Row 13: The percentages reported in this Amendment No. 6 are based on 10,600,684 shares of Common Stock deemed outstanding pursuant to Rule 13d-3(d)(1), calculated as the sum of 8,328,598 shares of Common Stock outstanding as of April 27, 2026 according to records of the Issuer, plus (i) 1,203,046 shares of Common Stock that are issuable upon conversion of the Series A Convertible Preferred Stock beneficially owned by Hu Bin and (ii) 1,069,040 shares of Common Stock that are issuable upon the exercise of warrants to purchase Common Stock beneficially owned by Hu Bin.

SCHEDULE 13D

CUSIP Number(s):

60365W102

Name of reporting person

Youxin Consulting Ltd.

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

HONG KONG

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 649,254.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 649,254.00
10	Shared Dispositive Power 0.00

Aggregate amount beneficially owned by each reporting person

649,254.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

7.2 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person:

Note to Rows 7, 9 and 11: The above-referenced shares of Common Stock beneficially owned by Youxin Consulting Limited ("Youxin Consulting") consist of (i) 343,774 shares of Common Stock issuable upon conversion of 245,553 shares of Series A Convertible Preferred Stock, which are convertible into shares of Common Stock per the Ratio and (ii) 305,480 shares of Common Stock issuable upon the exercise of warrants to purchase Common Stock. The shares of Series A Convertible Preferred Stock vote on an as-converted basis. Note to Row 13: The percentages reported in this Amendment No. 6 are based on 8,977,852 shares of Common Stock deemed outstanding pursuant to Rule 13d-3(d)(1), calculated as the sum of 8,328,598 shares of Common Stock outstanding as of April 27, 2026 according to records of the Issuer, plus (i) 343,774 shares of Common Stock that are issuable upon conversion of the Series A Convertible Preferred Stock beneficially owned by Youxin Consulting and (ii) 305,480 shares of Common Stock that are issuable upon the exercise of warrants to purchase Common Stock beneficially owned by Youxin Consulting.

SCHEDULE 13D

CUSIP Number(s):

60365W102

Name of reporting person

Li Wai Chung

Check the appropriate box if a member of a Group (See Instructions)

(a)

(b)

SEC use only

Source of funds (See Instructions)

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

Checkbox not checked

Citizenship or place of organization

HONG KONG

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 649,254.00
8	Shared Voting Power 0.00
9	Sole Dispositive Power 649,254.00
10	Shared Dispositive Power 0.00

Aggregate amount beneficially owned by each reporting person

649,254.00

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

Checkbox not checked

Percent of class represented by amount in Row (11)

7.2 %

Type of Reporting Person (See Instructions)

Comment for Type of Reporting Person:

Note to Rows 7, 9 and 11: The above-referenced shares of Common Stock beneficially owned by Li Wai Chung consist of (i) 343,774 shares of Common Stock issuable upon conversion of 245,553 shares of Series A Convertible Preferred Stock, which are convertible into shares of Common Stock per the Ratio and (ii) 305,480 shares of Common Stock issuable upon the exercise of warrants to purchase Common Stock. The shares of Series A Convertible Preferred Stock vote on an as-converted basis. Note to Row 13: The percentages reported in this Amendment No. 6 are based on 8,977,852 shares of Common Stock deemed outstanding pursuant to Rule 13d-3(d)(1), calculated as the sum of 8,328,598 shares of Common Stock outstanding as of April 27, 2026 according to records of the Issuer, plus (i) 343,774 shares of Common Stock that are issuable upon conversion of the Series A Convertible Preferred Stock beneficially owned by Li Wai Chung and (ii) 305,480 shares of Common Stock that are issuable upon the exercise of warrants to purchase Common Stock beneficially owned by Li Wai Chung.

SCHEDULE 13D

Item 1.

Security and Issuer

(a)

Title of Class of Securities:

Common Stock, $0.01 par value

(b)

Name of Issuer:

FiEE, Inc.

(c)

Address of Issuer's Principal Executive Offices:

3-33, 2-chome Utajima, Nishiyodogawa District, Osaka, JAPAN , 00000.

Item 1 Comment:

This Amendment No. 6 amends and supplements the Schedule 13D filed by Cao Yu, Hu Bin, Youxin Consulting and Li Wai Chung (collectively, the "Reporting Persons") on February 25, 2025 (as amended by Amendment No. 1, filed on April 14, 2025, Amendment No. 2, filed on May 13, 2025, Amendment No. 3, filed on May 29, 2025, Amendment No. 4, filed on August 25, 2025, and Amendment No. 5, filed on January 8, 2026, the "Schedule 13D"). This Amendment No. 6 is being filed solely due to an increase in the Issuer's total number of outstanding shares of Common Stock and not as a result of any transactions by the Reporting Persons. Except as specifically provided herein, this Amendment No. 6 does not modify any of the information previously reported in the Schedule 13D. Capitalized terms used but not defined in this Amendment No. 6 shall have the same meanings ascribed to them in the Schedule 13D.

Item 5.

Interest in Securities of the Issuer

(a)

See rows (11) and (13) of the cover pages to this Amendment No. 6 for the aggregate number of shares of Common Stock and percentages of the shares of Common Stock beneficially owned by the Reporting Persons.

(b)

See rows (7) through (10) of the cover pages to this Amendment No. 6 for the number of shares of Common Stock as to which the Reporting Persons have the sole or shared power to vote or direct the vote and sole or shared power to dispose or to direct the disposition.

(c)

The Reporting Persons have not effected any transactions in the Issuer's securities within the past 60 days preceding the date of this Amendment No. 6.

(d)

No other person is known to the Reporting Persons to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, the shares of Common Stock covered by this Amendment No. 6.

(e)

Not applicable.

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.

Cao Yu

Signature:	/s/ Cao Yu
Name/Title:	Cao Yu
Date:	05/04/2026

Hu Bin

Signature:	/s/ Hu Bin
Name/Title:	Hu Bin
Date:	05/04/2026

Youxin Consulting Ltd.

Signature:	/s/ Li Wai Chung
Name/Title:	Li Wai Chung
Date:	01/08/2026

Li Wai Chung

Signature:	/s/ Li Wai Chung
Name/Title:	Li Wai Chung
Date:	05/04/2026