The author's introduction is incompetent, why don't you read one or two before talking?
After traveling as Flandre and gaining the ability to travel across the world with someone's help, the first thing to do is to leave Gensokyo. Who wants to be imprisoned in a dark basement in the middle of winter? But, Gensokyo, I will definitely come back.
This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.