Kenritsu Umisora Koukou Yakyuubu-in Yamashita Tarou-kun

Tarou Yamashita is a hopless klutz, but his enthusiasm for baseball know no bounds! Inspired by his passion, the members of the Umisora High School Baseball Club decide to try to compete at the prestigious Koshien Stadium. The sight of the players slowly but surely improving over time got readers fired up in a way many other baseball manga couldn't.

(Source: Shueisha, translated)

Included one-shots:
Volume 21: Umisora Koukou 4-ban Sanrui Yamashita Tarou-kun, Umisora Koukou 5-ban Pitcher Yamashita Tarou-kun