Subaru Natsuki Wanders into Gensokyo

[Re:Zero's Natsuki Subaru] + [Touhou Project] + [Subaru x Rem TV] What would happen if, after Natsuki Subaru left a convenience store, he met a youkai sage calling herself “Yukari Yakumo” and ended up in Gensokyo? ...He knelt on one knee before Remilia, his expression solemn. “My lady, I won't let your kindness go unrepaid!” ...Dressed in a butler's uniform, he looked at Sakuya Izayoi with a smile. “Miss Sakuya, please let me become ‘perfect’ too!” ...He held out a handmade doll to Flandre, then gently patted her head. “Flandre, let me play with you!” ...He bowed to Hong Meiling, his eyes burning with passion. “Master Hong, I want to get even stronger!” ...But when he walked into the library, he discovered... “Wait... why has Miss Patchouli fainted again? And Marisa, when did you sneak in to steal books again?” ...Anyway, dressed in his butler's uniform, Natsuki Subaru turned back with a smile to face everyone in the Scarlet Devil Mansion. “Don't worry, leave it all to me!” “After all... I, Natsuki Subaru, am a man destined to conquer another world!” “And, of course, I'll also be the Scarlet Devil Mansion's most perfect butler!”