My wife, Yui, is a beautiful and elegant woman. One day, a man named Isobe, who claims to be my wife's former teacher, came to our house. He had a bad vibe about him, so I sent him home early... A few days later, I found Isobe's smartphone stuck in the gap of the sofa. I'm sure I cleaned this place yesterday... so did Isobe come to our house again between yesterday and now? What on earth was he doing there? Despite having a bad feeling, I looked inside the smartphone to find out the truth...