My name is Hiroshi, and I've been dating my girlfriend for half a year. She's kind, beautiful, and has a calm, mature charm. Her mother, Yumi, is a single mother who raised her daughter all on her own. My relationship with my girlfriend has always been pure and warm, but one day, behind her back, I ended up sleeping with her mother. Now, I live each day with complicated emotions. Though both Yumi and I know this affair is wrong, we can't suppress our desires, and we're deeply troubled by our ongoing involvement.