All's Fair in Love and War(2020)

Tategami ni I Love You

At a high school full of delinquents, Leo Shishiyama, a boy who looked cute but was the best fighter, is puzzled. Takeru Kurosawa, who had constantly challenging Leo to fights that ended up in a draw, has sent him an eighth challenge letter. Leo likes winning, but he doesn't particularly like fighting, and enjoys gorging on strawberry rice cakes, his favorite snack, much more. He tries to ignore Takeru, but bumps into his beautiful little sister on the street, who shows him kindness. If he can beat Takeru, maybe he can make a move on her! Leo faces Takeru, but who comes out victorious...?

(Source: Renta!)