Ask your sister to teach you how to kiss

Suzu returns to her parents' house after arguing with her husband. Suzu's younger brother is in love with a classmate, but is cruelly rejected. Feeling that he lacks kissing experience, his younger brother came to Suzu to help him improve. Although she didn't want to, seeing her younger brother was desperate, Suzu agreed.

However, she placed a small glass to separate their lips. But her younger brother couldn't control himself and wanted to go further. In the end, the two of them did something they couldn't turn back from...