The protagonist has just found a new job, and will be leaving her prefecture in Spring to start.
She heads to the rundown shrine near her to speak of the news, but finds a mysterious, weak-looking man passed out.
She decides to nurse him back to health until spring...
The otherworldly man finally comes to get some life in him, but his attachment to her grows to an unhealthy level.
"I want to be with you forever."
Before the protagonist realizes it, she has reached the point of no return.