Touhou Outsider

A mysterious entity known as Yukari Yakumo popped up in Zomazenta and stole a mini golden Buddha statute from the temple of seals upon carrying it back to Gensokyo for the new power source she knowingly brought back someone with her since she wanted to test this person.

This is the story of how Hart ended up in Gensokyo the land of illusions is what it's known to for many who has been there.