So this manga is a side story of Tusyogari by NEKOTA Yonezou
Is about Keisuke and Aki who are already grown up.
Aki and Keisuke are going through a dry spell, bc Aki doesnt want to show Keisuke how much he has grown, I think he is afraid Keisuke might hate him.

Thank you for reading, I appreciate the help

It's an extra from Tsuyogari scanned by Nakama, but I don't know if they still have it since it's published by Libre that right now is requesting the scanlators to delete all the scanlations 🙁