Yūsuke Shiina is one of the three main characters in "Jigokudō Reikai Tsūshin." He belongs to a notorious elementary school trio called the "Itazura Daiō Sannin Waru" (Mischief King Trio of Mischief), alongside the nicknamed characters Tecchan and Ryōchin. This group of troublemakers accidentally opens a portal to the supernatural world during a visit to the Jigokudō (Hell Hall) pharmacy.