Tooru Amamiya is the childhood friend and ex-boyfriend of Yuki Kurokawa and the main antagonist of the manga series GE Good Ending. Despite not appearing fully in person towards the end of the story his presence is felt throughout the series as he is the reason why Yuki and Seiji had a complex and diffcult relationship and were unable to truly love each other until he was finally confronted by the pair. Plus due to his dark past with Yuki she has deep scars that were ultimately his doing which leads to his having a behind the scenes villianess presence.