Sougen Esaka
A gentleman who runs an antique shop business in the city of Kazamatsuri. After meeting Kotarou on a certain occasion, he grants him advice that draws from his vast life experience. Although calling himself a "totally humorous, somewhat mischievous businessman", his gags oppositely charm everyone with fear. Spoiler A cutter-type superhuman in Guardian. He's a leader of a decorated instructional combat unit called Bayern Knights. He's Kotarou's mentor in the past when Kotarou was on Guardian. At the 2nd half of Terra: Spoiler He died as the result of his battle against Kotarou. (Source: Rewrite's Memory Section)