Sento (銭湯) are Japan's traditional public bathhouses — neighborhood institutions that predate home baths and still serve as community gathering places. They differ from onsen in that the water is heated tap water (not natural hot spring), but the bathing culture, social ritual, and design can be equally compelling.
Sento vs. Onsen
Sento: Public bathhouse using heated tap water. Usually cheaper (¥500–¥600). Found in cities and residential neighborhoods. Often architecturally interesting (traditional sento architecture with high ceilings, mosaic tiles, Mount Fuji murals). Some "super sento" use artificial mineral additives. Onsen: Natural hot spring — specific mineral content from geothermal sources, claimed therapeutic benefits. More dramatic settings (mountain, volcanic). More expensive (¥800–¥3,000+ day use).
How to Use a Sento
1. Pay at the entrance counter (¥490–¥600 in Tokyo, ¥490 is the official Tokyo price). Buy or borrow towels if needed (¥50–¥100 for small towel). 2. Change in the locker room (genkan area) — put clothes in a basket or locker. 3. Take a small towel (don't bring it into the bath), wash bag if you have one. 4. Sit at a wooden stool in the washing area — shower down and scrub thoroughly. 5. Enter the bath. Soak as long as comfortable. 6. Exit, towel dry in the changing area. The whole process takes 30–60 minutes.
What to Bring
Small towel (for modesty — fold on head while bathing, not in water). Body wash and shampoo (available to buy at the counter if forgotten). Brush or comb. Flip-flops if the floor seems slippery.
Traditional Sento Design
Classic sento have: high vaulted ceilings with ventilation, large tile murals (typically Mt. Fuji or sea scenes behind the baths), wooden locker rooms with attendants at a high desk between the men's and women's sides. This design is increasingly rare — newer sento and "super sento" tend toward modern spa aesthetics.
Notable Sento in Tokyo
Daikoku-yu (Katsushika): Beautiful traditional architecture, jet baths, open-air section. ¥500. Kotobuki-yu (Koenji): Renovated with striking contemporary design, roof deck. ¥550. Shimizu-yu (Minami-Aoyama): Ultra-modern spa sento near Omotesando. ¥1,200. Jakotsu-yu (Asakusa): Natural hot spring water imported by tanker — the rarest (and best) of both worlds. ¥700.
Sento Etiquette
Same rules as onsen: wash before entering, no towel in water, be quiet, tattoos may be restricted (ask). Sento are slightly more relaxed than high-end ryokan onsen about tattoos — a small tattoo is often overlooked, but large visible tattoos may still be turned away.