Girl loves some guy who constantly wore armor and saved her in many ways multiple years ago, but then died saving her and entire town from dragons. She buried him and has been looking for some way to resurrect him as she realized she loved the dood.
Guy had a chuuni period as a kid where he wanted to become a hero. So he among other stuff invented a delayed resurrection spell, that has the drawback of sometimes deleting memories and even reviving you away from where you died in both time and space if body was too damaged. It makes him unable to heal.
He also seems to avoid women whenever they show favour to him, and stopped wanting to be a hero now for whatever reason.
She superimposed mc on the dead guy she loved as she and mc have been 'dating' last few chapters, and feels bad for it. But now she randomly superimposed harder, and convinced herself that mc is the dead guy because of some circumstantial evidence (he mentions having died around same period, fighting a dragon, in similar region, after having mentored some kid girl feeding her potions and giving her a name), and so decided to confess to him before he dies again.
Mc is going to flee again, as entire reason he is pretending to be a teacher was because he fled from hero girl party etc.
