Zettai Himitsu no Kikai Shoujo

Mameo's family has run a ryokan for 100 years, but now it's on the verge of shutting down. In a last-ditch effort, his mom buys an AN-C, a state of the art, highly realistic android. However, he finds out that it's actually just a girl pretending to be an android in a scheme to pay off her debt! With their destruction mutually ensured if anybody finds out, Mameo agrees to help keep her secret at all costs.

[Written by Denji]