a few years ago there was a zombie apocalypse all over the city, Tsukasa and Rui promised each other that they would never leave each other and they would survive this apocalypse together.

they had just finished fighting zombies, Tsukasa looked at Rui who was exhausted just like him.

"we did it.. again.." Tsukasa was breathing heavily after that fight, there were a lot of zombies this time.