Naviko

One day, after waking up drunk in a park, Mizutani is approached by a mysterious girl named Navi. She informs him that she has paid off his debts on his behalf—and in exchange for this favor, she demands that he assist her with a business venture she is planning to launch. Unable to make sense of the situation, Mizutani attempts to flee from Navi, but the enigmatic girl effortlessly corners him... And so begins their peculiar business partnership. A whimsical and slightly mysterious fantasy tale of architectural exploration!

(Source: Shinchosha, machine translated)

Original Japanese: cmoa