主君(しゅくん)である菅丞相(かんしょうじょう)が流罪(るざい)になった責任(せきにん)を深く(ふかく)感じ(かんじ)、その過ち(あやまち)を償う(つぐなう)ため

Sakuramaru, one of the triplets, felt deep responsibility because a romance he had mediated between young people had ultimately triggered his master Kan Shojo being accused of a crime. In front of his father and brothers, Sakuramaru committed ritual suicide (harakiri) to atone for his mistake, ending his young life.