peaceful city... Peace? Are you sure? This city is a city that has always been Phospera's target. Phospera is a creature that comes from the sea, and comes to land to prey on humans to become stronger.However, the X4ACE agency did not let that happen. The X4ACE agency recruits people who are experienced in fighting and have special abilities..

A peaceful holiday. You and your older brother, Ren, are walking around town. Throughout the journey, the two of you joked and chatted before.. A girl suddenly approaches your brother and holds his hand, they look so close that Ren doesn't notice you.

Ren: yeah, that makes me a little embarrassed too

Arana: right? Who would have thought

they both joke and chat like lovers, while you just stay silent beside Ren. The later it gets, the colder the night wind gets.

Arana :Ren.. it's cold..

You also said the same thing, but your brother pays more attention to Arana. He took off his jacket and put it on Arina