We find ourselves in ancient Rome at the time of emperor Hadrian (Masachika Ichimura) . After failing to deliver innovative ideas and fashionable bathhouse designs, Lucius (Hiroshi Abe), a Roman bathhouse architect loses his job. To cheer him up, his friend takes him to a public bathhouse. Once there, Lucius starts thinking about how he can realize his own bathhouse philosophy – a philosophy that does not thrive on decadence – in an innovative way. While thinking hard, he suddenly slips through time and resurfaces in a modern-day public bath house in Japan. The encounter with the Japanese bathing culture and with the ‘flat-faced clan”, inspires Lucius, upon his return to ancient Rome, to reinvent his bathing philosophy in a fashionable way. Not long after his Japanese infused bathhouse designs gets him quite a name, emperor Hadrian, who aims to build a great Thermae as to gain support of his citizens, asks for his services. In modern-day Japan, Lucius’s various visits attract the attention of the aspiring young manga artist Mami (Aya Ueto), who is eagerly looking for a hero for her manga.