The character 水 at a glance
水 (mizu in kun'yomi, sui in on'yomi) represents water in Japanese. The character depicts flowing water — you can see the central vertical stroke as the main current, with smaller strokes branching away like rivulets. It is one of the oldest and most visually intuitive kanji.
水 is also Wednesday's element (水曜日, suiyoubi) and one of the five classical elements in East Asian cosmology alongside 木 (wood), 火 (fire), 土 (earth), and 金 (metal/gold).
水 in compound words
水 appears in an enormous number of everyday Japanese words: 水道 (suidou — waterworks/tap water), 水泳 (suiei — swimming), 洪水 (kouzui — flood), 水分 (suibun — moisture/hydration), 飲み水 (nomimizu — drinking water), 水曜日 (suiyoubi — Wednesday), 水族館 (suizokukan — aquarium).
The water radical (氵), a three-stroke simplified version of 水, appears in over 100 kanji related to liquids, flow, and moisture: 海 (sea), 湖 (lake), 泳 (swim), 涙 (tears), 深 (deep).
水 has two distinct readings used in different contexts. 水 alone is almost always read mizu (kun'yomi). In compounds — especially formal or scientific ones — the on'yomi sui is used: 水分 (suibun), 水泳 (suiei). Context makes it clear which reading applies.
Water in Japanese culture and philosophy
Water holds special significance in Japanese aesthetics. The concept of mizu no kokoro (心 of water — a calm, still mind) is central to martial arts philosophy. The Japanese garden tradition (karesansui) uses raked gravel to represent flowing water without a drop of actual liquid. And omizutori — the water-drawing ceremony at Tōdai-ji temple — has been performed every March for over 1,200 years.
See the water kanji page
Full readings, example words, and stroke order for 水.