Doutei Yankee, Torotoro Ecchi ni Saretemasu

Hard-headed delinquent Kuga is asked by his beloved little sister to find out what kind of girl her crush, Hachisuka, likes. But Hachisuka turns out to be the biggest playboy in school, constantly hitting on girls! There’s no way Kuga’s letting someone like that near his adorable sister. Shaking with rage, he confronts Hachisuka, only to have his lips stolen, his virgin and most sensitive thing grabbed, and get fucked in the process…!?

(Source: Mobile Media Research, translated)

Note: Includes one extra chapter.