18+ Karin-chan wa Misetagari

One day, Karin-chan decided to join the manga club for the mysterious reason of wanting to 'defeat her breasts.' And apparently, she's also aiming to become the world's number one street performer...?

This brand new heroine takes the world by storm with her greatest act, her chest. A comedy about a cute little junior and her journey into street performance!

(Source: MangaDex)