Fox demon: Carry my piano music with me forever

Source name: Fox Demon: Carry my piano music with me and accompany me forever
Alias:
Tags: anime derivative, time travel, system, two-dimensional, invincible, single female lead, fan fiction, 1v1, no harem
Main characters: Fu Changsheng, Tushan Rongrong
Introduction: [Fox Spirit Matchmaker] [Single Female Lead Tushan Rongrong]
One person, one piano, walking among the vast stars, overlooking the mortal world
He is both the last mask and the last human emperor.
He should have been strong enough to dominate the world, walking on the path of licking blood on the tip of a knife, but he became invincible in the midst of laughter and joy.
I thought I could live a carefree life, but I met an enemy.
"Fu, tell me clearly who that woman is!" Tushan Rongrong chased Fu Changsheng with an abacus in her hand.
"I really don't know her!"
"You don't even know her, but she's still giving you a hundred taels? Go to hell!"
Fu Changsheng: "I once bore the lies of the world, and killed people everywhere in a bloody robe. I once looked at the stars and sang with one person."
Tu Shan Rong Rong: "Oh? Pretty impressive (takes off glasses), come, let me see!"