TV-Series
Description
The Old Guy at the Public Bath is a minor supporting character in the anime Thermae Romae, listed in Japanese materials as Sentou no Oyaji, a name meaning old man of the bathhouse. He is an elderly Japanese man who appears as a customer at a traditional public bath, or sento, in the modern world, and he features in the first half of the opening episode of the 2012 television anime.

Background: He belongs to the everyday world of a neighborhood bathhouse in contemporary Japan. On the day the story begins, he is present at the sento when the ancient Roman bath architect Lucius Modestus is unexpectedly transported through a mysterious drain and surfaces in the modern bath after traveling through time from ancient Rome. The old man is therefore among the first modern Japanese people Lucius encounters.

Personality: He comes across as an ordinary, longstanding patron of the local bath. He treats the sento as a familiar and relaxed place and reacts to the sudden appearance of a strange, heavily tanned foreigner with plain curiosity and puzzlement. Since he and Lucius share no common language, their encounter is a confused exchange of gestures and attempts at speech, and he is unable to understand who Lucius is or where he has come from.

Motivations: His motivations are entirely those of daily life. He visits the bathhouse to wash and soak, as regular customers do, and he has no personal agenda beyond his ordinary routine. His interest in Lucius is simply the natural reaction of an elderly regular who finds an inexplicable stranger in familiar surroundings.

Role in the story: He serves as a representative of the modern Japanese public, the people Lucius labels the flat-faced tribe. His brief appearance demonstrates how ordinary Japanese bathing culture is completely foreign to the Roman visitor, and his baffled interaction with Lucius contributes to the comedy of the episode by showing both sides trying and failing to understand each other. In structural terms, he anchors the beginning of Lucius's first exposure to modern Japan.

Key relationships: His only meaningful relationship in the story is with Lucius, and it lasts for a single scene. The interaction is based on mutual misunderstanding, as neither character can speak the other's language and neither can explain what is happening. He has no defined connection with any other named character.

Development: He does not develop as a character. He appears in one limited portion of a single episode and is never seen again, so he has no arc or change over the course of the anime.

Notable abilities: He has no special abilities or unusual skills. His contribution to the story is simply being an unremarkable elderly bather, and his value to the narrative lies in the ordinariness of his presence rather than in any particular talent.