[Lithium no Kojin Circle (Lithium)] Tanaka-kun ga Boku-tachi no Mae de Kyoudai Sex Shita Hi no Koto Bangaihen [Schale Scans]

A shy brother and his curious sister share a steamy bath, discovering the thrill of intimate play in a cramped bathroom. Their innocent conversation quickly turns into a daring exchange of teasing touches, secret whispers, and the rush of a sudden, unexpected climax. The story builds toward a forbidden reunion at a private house, leaving the siblings on the edge of desire and secrecy.