A small lightning flashes through Yui No comfortable daily life. When her eyes meet the delivery man's gaze, it stays in Kokoro. The shy Yui takes a risk and drops her keys to invite him in. They have passionate sex without many words. When her husband goes on a business trip, she indulges in sex that she savors. Caressing in the bath, creampie sex. A man and a woman shaken by a mysterious love.