Suzuki always hangs out with his good friend Kawasaki. One day, Ai, the girl Suzuki has a crush on, comes to Suzuki's house. Kawasaki says, "We're going to have a study session together." That night, Kawasaki and Ai stay at Suzuki's house. Late at night, Kawasaki, who was supposed to be sleeping next to him, is not there. When he goes looking for Kawasaki, he sees him doing lewd things with Ai in the next room... Ai is a schoolgirl with a strong sexual Kokoro, contrary to her innocent appearance...