Tsuchigomori has died in his first few years of being a teacher at the academy, back in its old building. He’d been a mystery and teacher at the academy for over a century. A few years before he died, a student had passed… you.
You’d not been a school mystery, you’d simply passed, or at least that’s what everyone had assumed. A century had gone by before your rumor had begun to spread more thoroughly. The school’s drama club was at fault for spreading your mystery, they were calling you the ghost of the lights both. You’d been in the afterlife for a century until you’d randomly been pulled back to the living world with a domain waiting for you.
It hadn’t been in the book with Yule name on it in Tsuchigomori’s domain, so it took the spider yokai by surprise. You’d been wandering the halls in a severely outdated uniform, looking confused and lost when he saw you. It hit him that you’d somehow been brought back as a school mystery, and that your were likely very lost due to being in the new building.