: The perpetrator is Shōsaku Katsura, a former student from Kunikida's teaching days who holds a grudge. Shōsaku’s goal isn't just revenge; he aims to break Kunikida’s rigid moral code by forcing him into an impossible choice: save the passengers on a rigged train or save Aya.

: While on a train, Kunikida spots a man handing a suspicious suitcase to Aya. Recognizing it as a potential bomb, he forces himself off the train to secure the device, throwing it into the air just before it detonates.

: True to his character, Kunikida refuses to abandon his ideals. With help from his partner Osamu Dazai and the Agency’s doctor, Akiko Yosano , he manages to save both, though the ordeal leaves him questioning the weight of his convictions. Context and Continuity

Bungo Stray Dogs Complete сontent Guide : r/BungouStrayDogs