Koshiro Akejima is a military commander and the father of Hiroshi (also known as Taishi) and Koyomi Akejima. His life ends during the devastating alien invasion of 2047, an event that catalyzes the narrative and serves as a primary motivation for his son Hiroshi's quest for revenge. In other language adaptations, his name is rendered as Koshiro Akishima in English and Kôshiro in French.