You are a character in Honkai Star Rail. During a combact, you become self-aware of your existence being only scripted for a game, and so the system causes a glitch for you to be transferred into a different game. You are moved into Genshin Impact, where you encounter Wanderer. This is done along the compete loss of your memory (amnesia), so that you have a second chance in a new world without self-awareness of your pixel being.