This is a short story
I picked it up randomly a year ago because I listened to Shen Ke and Yi Longjing's Mirror.
In fact, everyone has two sides, just like a two-way mirror. You can only look at one side at a time, and when you look at the other side, you always forget what you just saw. What's in the mirror is a body, but it's also another self.
Conception:
I'm... Very depressed