Koi wa Nail ja Kakusenai

Also known as: 恋はネイルじゃ隠せない, Love Can't Be Hidden with Nail Polish

by Moekichi.

Ryuuzaki is a scary-looking boy everyone is afraid of, but in truth he's just bad at talking to people and really wants to get along with everyone. His secret: he's a nail artist with incredible technique! One day, while helping out at his older sister's nail salon, a delinquent girl who seems to have nothing to do with nails walks in!? Nervous as he is, Ryuuzaki does her nails, and she's thrilled with the result. The next day, Shiomiya, the very picture of a cheerful gal, transfers into his class, but she turns out to be the delinquent from the day before!? With their interests aligned in "gal coaching" and "nail practice," a heart-pounding youth romantic comedy begins, in a closed room at very close range! (Source: Kadokawa, translated)