Shiou no Kikan: Moto Yuusha no Ore, Jibun ga Soshiki Shita Chuuni Himitsu Kessha o Tomeru tame ni Futatabi Isekai ni Shoukan Sareteshimau

屍王の帰還　～元勇者の俺、自分が組織した厨二秘密結社を止めるために再び異世界に召喚されてしまう～

"How can my past self get so excited doing all those embarrassing things!?" When he was in the third year of middle school, Hizaki Shiou was summoned to another world to save it.