The serious and gentlemanly student is actually a fierce yakuza member! Show me what's beyond a kiss...

Kanon Yamagishi, aged 27, is a piano instructor. She has a secret crush on Ryuuichi Suwa, a handsome older man who takes her lessons, but Kanon is a sheltered woman with no experience with men so she can only daydream... Then, one day on her day off, she runs into Ryuuichi at a music store where she went to buy sheet music. She helps him with his errand, and then he invites her over to his home to thank her...