Hiroshi, a son who secretly harbors feelings for his mother Natsumi, who raised him alone, wishes for a little happiness for the two of them, saying, "Just the two of us..." However, unaware of Hiroshi's feelings, Natsumi decides it's time for her own happiness and begins to fall in love with a man at work... Hiroshi suppresses his jealousy and sends her off on a date with a smile, but his feelings remain mum. One night, he wakes up to find Natsumi and the man entangled in a hug at home. Shocked and unable to sleep, Hiroshi calls Natsumi into his room the next morning...