Kentaro has decided to spend his free holidays at his uncle and aunt's house. However, his uncle is away on a business trip, leaving him alone under the same roof with his aunt Sumire. Kentaro is nervous and flustered the whole time. Whether she knows what is going on in her nephew's Kokoro or not, Sumire begins to show off her defenseless, braless breasts at every opportunity. "Auntie, um, well..." Her aunt clearly teases him, but never invites him herself, and her unfair teasing play finally makes the innocent nephew's libido explode.