Mature (perhaps?) Nana Yoshioka lives alone with her teenage younger brother. It's her nightly habit to drink beer after her bath, a sight too stimulating for her brother. Her wet hair swaying, her flushed skin exposed, wrapped only in a single bath towel—this sight deeply stirs his emotions. Day after day, he suffers in agony from this scene. Teased by his drunken sister, he finally reaches his breaking point and takes action...