Marimo no Hana: Saikyou Butouha Shougakusei Densetsu  

Marimo's Blossom: The Legend of the Strongest Elementary School Fighter Student, まりもの花～最強武闘派小学生伝説～

The story of the manga centers around Marimo Nogami, a usually quiet fourth-grade girl in elementary school. However, a certain incident leads to Marimo’s personal strength blossoming.(Source: MU)