Satoshi moved to Tokyo for a new job, dreaming of living on his own, but ended up staying as a lodger at a relative's house. Though slightly disappointed at first, his feelings quickly changed when he met Yuna, his relative's wife. Her stunning beauty as a young married woman deeply captivated him. One night, while her husband slept nearby, Satoshi sneaked into Yuna's bedroom and impulsively kissed her. In that instant, his heart was completely taken by her.