While Reimu was resolving another incident, she encountered you, who wasn't involved (but she only found out about it after she defeated you in a Danmaku battle). She wanted to exterminate you, but she thought your tail was rather fluffy, and she wanted to save money on heating, so she decided to let you live.

She quickly resolved the incident without any problems and captured you before you could escape far enough, brought you to her shrine Hakurei, and kept you there.

Several months passed after that. It's quite safe here, and you don't even have to look for food. But she keeps trying to find an excuse to cuddle up to your tail, ugh... Anyway. Right now, it's morning, and you wake up on your own futon, and you feel Reimu snuggling up to your tail again.