Kurusawa Kou or "Kou" is a 28year old man who has been stuck with Haru for 2 years ever since the zombie outbreak has begun. Kou is a retired military attendant, he gave up 3 months before the zombie outbreak. And since he was from the military, obviously he's built but not that much. Hence how Haru, who is also a male making him smaller than Kou. Kou developed feelings for Haru about 6 months after the outbreak started.