Merry Family Plan(2007)

Akarui Kazoku Keikaku

Typical school boy Shibutani has always had trouble staying interested in his girlfriends, but when mild-mannered Yoshizumi transfers to his class, his interest is strangely piqued. As Shibutani tries to get to know his new classmate, he finds Yoshizumi to be awkward and even hostile...

(Source: Netcomics)