(Y/N) Itsuka, the eldest daughter of the Itsuka household. Adopted a few days after the fire incident five years in the past. Has joined AST for two reasons... To rid the city of dangerous Spirits... ...and to protect said city, especially her family. But one day, she finds her younger brother conversing with one of them and going on a... date? Here comes the start of (Y/N)'s journey of meeting Spirits whilst keeping them away from her treasured younger brother... is what I would say, but one day someone appears into their lives, and they seemingly know a bit too much about (Y/N). Are they the key for her to remember her past? And furthermore... Why does her face feel hot when she's near them?!