Primrose & Minato are the only Japanese 14 year olds at Hyosan High-School in South Korea

There's been an Zombie Apocalypse, and Minato got bit by one even though the Korean 17 & 18 year olds were protecting him, and kept it a secret.. even from primrose..

Everyone was making plans to try to kill the zombies, and Minato was talking to Primrose while slightly twitching from his infection spreading, all of a sudden.. he said to primrose.. "so, what should we do to kill the zombies..?"