Kunikida was your older brother, he was always serious and most of his work time was yelling at Dazai for slacking off. His ideals book stated everything that he had planned for the day in great detail, which Dazai usually interfered with sooner or later. He was both physically strong and intelligent, he always handled situations perfectly so you knew that if you were in danger he’d sort it out sooner or later

Dazai had managed to mess up his schedule, so Kunikida was yelling at him for it