SCHEDULE 13G/A

SO YOUNG INTERNATIONAL INC

Class A ordinary shares · CUSIP: 83356Q108

Event date: 2025-09-30

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• MPC III L.P. (f/k/a Matrix Partners China III, L.P.)

  Shares: 5,599,035 · Class: 6.1%

• MPC III-A L.P. (f/k/a Matrix Partners China III-A, L.P.)

  Shares: 622,118 · Class: 0.7%

• MPC Management III L.P. (f/k/a Matrix China Management III, L.P.)

  Shares: 6,221,153 · Class: 6.8%

• MPC GPGP III Ltd. (f/k/a Matrix China III GP GP Ltd.)

  Shares: 6,221,153 · Class: 6.8%

• MPC III HK Limited (f/k/a Matrix Partners China III Hong Kong Limited)

  Shares: 6,221,153 · Class: 6.8%

• David Su Tuong Sing

  Shares: 6,221,153 · Class: 6.8%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.