Meaning
湯 means hot water, bath, and hot spring. In everyday Japanese life, this character appears constantly — from the simple act of boiling water to the ritual of soaking in a public bathhouse. Knowing this kanji puts you at the center of one of Japan's most distinctive daily practices: the bath.
Etymologically, 湯 is a compound ideograph. The left side is 氵 (sanzui), the three-stroke water radical, signaling that the character relates to liquid or water. The right side is 昜, an older component associated with the sun rising and radiating warmth and light. Together, they paint a vivid picture: water heated by the sun's rays — steaming, warm water. Once you see its construction, 湯 becomes one of the more intuitive kanji to remember.
湯 has 12 strokes and is taught in Grade 3 of Japanese elementary school, meaning most children master it around age 8–9. Its radical is 氵 (water), placing it alongside kanji like 海 (sea), 泳 (swim), and 洗 (wash). In Chinese, 湯 (tāng) means soup or broth. Japanese kept the character but shifted the meaning toward hot water and bathing — same shape, different life.
湯 carries more than its dictionary definition. Japan's onsen culture and the neighborhood sentō (public bathhouse) both center on 湯 — hot water as ritual, not just function.
Readings
On'yomi (音読み) — Chinese-derived readings
湯's on'yomi is トウ (tō). It shows up in Chinese-origin compounds — hot springs, medicinal baths, formal writing. Less common in casual speech, but frequent in place names and specialist vocabulary.
- 銭湯 (sentō) — public bathhouse; the neighborhood bath facility where people pay a small fee to bathe
- 湯治 (tōji) — hot spring cure; staying at a hot spring resort for therapeutic purposes
- 熱湯 (nettō) — boiling water; extremely hot water, used in cooking or sterilization
Kun'yomi (訓読み) — Native Japanese readings
The kun'yomi ゆ (yu) is the everyday reading. Running a bath, boiling water for tea, heading to the onsen — all ゆ. You'll encounter it constantly: in the kitchen, at the neighborhood sentō, in onsen towns across Japan.
- お湯 (oyu) — hot water (polite form); the standard everyday word for hot water
- 湯船 (yubune) — bathtub; the vessel you fill with hot water for soaking
- 湯気 (yuge) — steam; the vapor rising from hot water or hot food
Common Words & Compounds
Here are the key compounds, grouped by context:
Daily Life & Bathing
- お湯 (oyu) — hot water; the polite, everyday term
- 湯船 (yubune) — bathtub; specifically the soaking tub filled with hot water
- 湯気 (yuge) — steam, vapor; the wispy mist rising from a hot bowl of ramen or a steaming bath
- 湯冷め (yuzame) — getting chilled after a bath; the uncomfortable sensation of cooling down too quickly after bathing
- 湯のみ (yunomi) — Japanese teacup; a small ceramic cup traditionally used for green tea
Hot Springs & Public Baths
- 銭湯 (sentō) — public bathhouse; a neighborhood institution where people pay to soak together
- 温湯 (ontō) — warm spring water; a gentler, therapeutic hot spring
- 湯治 (tōji) — hot spring therapy; extended stays at onsen for health benefits
Cooking & Kitchen
- 熱湯 (nettō) — boiling water; used in cooking instructions, instant noodle packages, and safety warnings
- 白湯 (sayu) — plain boiled water; water that has been boiled and cooled slightly, sometimes drunk for health
- 湯水 (yumizu) — hot and cold water; also used idiomatically as in 湯水のように使う (to spend like water)
Miscellaneous
- 湯たんぽ (yutanpo) — hot water bottle; a traditional warming device placed in bed on cold nights
- 上湯 (jōtō) — high-quality soup stock; used in Chinese-style Japanese cooking
Example Sentences
お湯が沸きました。
Oyu ga wakimashita.
The hot water has boiled.
毎晩、湯船に入ります。
Maiban, yubune ni hairimasu.
I soak in the bathtub every night.
熱湯に気をつけてください。
Nettō ni ki wo tsukete kudasai.
Please be careful with the boiling water.
鍋から湯気が立っています。
Nabe kara yuge ga tatte imasu.
Steam is rising from the pot.
近所の銭湯は古くて居心地がいいです。
Kinjo no sentō wa furukute igokochi ga ii desu.
The local public bathhouse is old and very comfortable.
カップラーメンには熱湯を注いでください。
Kappu rāmen ni wa nettō wo sosoide kudasai.
Please pour boiling water into the cup noodles.
湯治のために温泉地へ行きました。
Tōji no tame ni onsenchi e ikimashita.
I went to a hot spring resort for therapeutic bathing.
寒い夜は湯たんぽが一番です。
Samui yoru wa yutanpo ga ichiban desu.
On cold nights, nothing beats a hot water bottle.
彼はお金を湯水のように使う。
Kare wa okane wo yumizu no yō ni tsukau.
He spends money like water.
Memory Tip
Picture this scene: a large pot of water sits in bright sunlight. The sun's rays — represented by the 昜 component on the right — beat down on it. The three water drops on the left (氵) begin to shimmer and heat up. That sun-warmed water is 湯. Every time you see 湯, imagine steam rising from a sun-drenched pot. Or picture it curling up from a hillside onsen ringed by autumn maples. That steamy warmth is ゆ.