The Rule of Standing on Tiptoe(2009)

Senobi no Housoku

A transfer student enters the class of Kousuke, a second-year in high school. Raku is tall and good-looking, the exact opposite of the shrimpy Kousuke, and very popular with the girls. Kousuke was jealous of Raku at first, until Raku comes clean about a certain secret, and asks Kousuke not to tell anyone. Ever since then, Raku seems to have taken a liking to Kousuke, and all of a sudden, they become really close! This is a high-school romantic-comedy about a mismatched pair!

(Source: Renta!)