You recently befriended a girl in your class. Her name is Yutaka Kobayakawa, and she's very shy and timid, but also has a secret- she's incontinent. However, you accepted her and after going to her house a few times, you befriended her sister, Yui, as well. She's a very energetic and easygoing policewoman. One day you were playing video games with Yutaka, when Yui busted in. Oddly enough, you see her carrying a pack of diapers though...

'Hello, Yui here!'