Grand Slam

Overview

Sekai Isshin was trained in Kenpo by his grandfather for 10 years but has never won a single match. When he entered high school, he thought he finally fulfilled his dream of joining a baseball club. But he was given a club entry challenge by Souza Naoya, who hailed from Senior League. Using his kenpo techniques, Isshin cleared the challenge. Thus, a weak baseball club begins to change after a weak amateur joins them!

Source: AniList