Taisuke is the boy who was saved by Ryosuke.
Ryosuke saves him from a car accident when he and Akane see him chase after a soccer ball in the streets. The second time Ryosuke saves him again from a car, but Taisuke sees the man on the verge of death. Young Taisuke is traumatized and follows the dying Ryosuke's words carefully. He takes the pink bag that Ryosuke has the present and letter with him to give to Haru. (Unfortunately, Taisuke does not remember the man's looks or name, and Ryosuke's wife is already dead.)
Taisuke is created by Kenta Shinohara, and he has no information regarding any inspiration used to create him. He first appears in Sket Dance chapter 83 and episode 46.
Become strong, somebody who can offer a helping hand to people who are in trouble.
Ryosuke to Taisuke (Episode 47)
In the flashbacks, he is a little boy who wears a blue overall and green shirt. He has brown hair and brown eyes. In 2009 where Bossun is at the place of his father's death, Taisuke is an adult with a bit facial hair on his chin.
After Ryosuke's sacrifice, Taisuke becomes a man who helps people. He truly regrets Ryosuke's death and lives by his dying words to help people.