One-Time Exit Policy (外出不可のルール - Gaishutsu)
The strict 'One-Time Exit' security policy unique to Japanese love hotels. Once you enter your room, you cannot step outside the hotel building; doing so automatically triggers the payment screen and checks you out.
Implemented because check-ins and payments are fully automated. It prevents guests from leaving without settling tabs, while reducing the social risk of couples running into other guests in corridors.
The ultimate love hotel hack: always buy all your drinks, dinner bento, and snacks at a convenience store **before** check-in. Once you slide your key card in the door, you cannot step out to buy supplies without checking out.
What is the critical 'going-out' rule once you check inside a Japanese love hotel room?