"Kei-neechan, you're the bad one..." He inserts it into the private area of his sleeping cousin... It's spring, and Yuuta has just become a full-fledged adult. On the condition that he does all of the house chores, Yuuta has moved into his cousin's place rent-free. Juggling both work and chores is tougher than he thought. Just as he is getting used to his new life, his cousin returns home completely drunk one day. She then rewards Yuuta for putting so much effort into the chores asking him, "Do you... want to play with my boobs?" It was only a joke, though, and then she falls asleep. Her ample breasts then meet Yuuta's eyes. He tells himself that this is bad, but convinces himself that, "she did say that I could touch them herself." He loses to his desires, then begins fondling her chest, undoing her bra, and escalating his actions... She lets out a soft, sweet sound and is wet down there in her sleep, which leads to him reaching his absolute limit...!