北舘 啓祐

Keisuke is Mitsuru's older brother, he was running a truck driver business. Years ago when Mitsuru was not yet an university student, he took him on his wing so that his little brother could quietly take off under his protection. His little brother is and makes him proud and after years of study, Mitsuru became someone and at the same time Keisuke met and bonded with Yura with whom he was going to marry.

A few months later, Keisuke has a car accident and died in the ambulance that took him to the hospital, leaving behind him his wife Yura and his newly born daughter, Mashiro.