Ace no Kyuujitsu

When his girlfriend dumps him, brash baseball pitcher Hidaka ends up alone on a 20 day cruise, drinking too much, getting into fights, and trying to pick up girls. The eccentric captain of the ship has brought his little son along with him, and when the ace can't even be bothered to give the boy an autograph, the captain decides the ship would be better off without the cocky ace.

(Source: MU)