Kango Yamazakura

A teacher at Asaoka High School and advisor to both the softball and boxing clubs. While in college, he worked toward becoming a professional boxer but gave up this dream after his sister died, in order to take care of his sister's daughter, Chika. He has a preoccupation with the female behind, and frequently gives unwanted attention to female students at the school.

[Spoiler] At the end of the anime series, he and Minatsu are married. [/Spoiler]

(Source: Wikipedia)