Sumire 16-sai!! - Vol. 4 Ch. 36 - Sumire and an Enjoyable Summer Vacation?! (Part 2)

[MangaDex]

 

[BakedBanana]

"If he were to lose the puppet right now, Youtsuya-san would return to a normal life..." (Page 13)

Well he's still got the mini Sumire probably. So he could pull a Detective Conan and act like she's shrunk to a child.