When one of the Filipinos went to the restroom, a Japanese woman grumbled that she should have held back in deference to the group schedule.

Owner Wang Tzi-wei opened his first Modern Toilet in 2004 after being inspired by a Japanese cartoon and the toilet themes run through the food and drinks menus.

Lavatories in Japan come in two forms: a traditional Japanese bathroom; and a uniquely Japanese take on a Western-style loo, adorned with buttons, lights and hi-tech features.