[Machine Translation] He was a communicator, a botch, and a shy guy in the Alaska summer. Kosei Masaki ( 30 years old ) was hit by a truck when he left a restaurant after the after-party of his junior's wedding. When he wakes up, his body is back to the age of 15, but for some reason he is in the modern world! He is now in a new world with a family that was not supposed to be there at the time, and his relationship with them is different than it was back then. He is now living in high school for the second time. This is the story of his life and adolescence.