海
うみ
umi
= sea; ocean
Japan is an island nation entirely surrounded by ocean, and 海 (umi) sits at the heart of its food culture, seasonal rhythms, and even its national calendar — the country dedicates a public holiday every July to the sea itself.
海 (umi) refers to the sea or ocean. While English speakers sometimes distinguish between a smaller “sea” and a vast “ocean,” Japanese uses 海 for both, relying on context or modifiers such as 大海 (taikai, “great ocean”) when scale matters. The word carries a warm, summery connotation in everyday speech — mentioning 海 in July immediately evokes crowded beaches and grilled corn on the cob. In more formal or literary contexts, 海 can evoke depth, vastness, and the unknown, as in the expression 海のように深い (like the depth of the ocean). The related word 海辺 (umibe) means “seaside,” and 海外 (kaigai, “beyond the sea”) is the standard word for “overseas” or “abroad.”
A common point of confusion for learners is 海外 (kaigai). Although it literally means “beyond the sea,” it is used wherever English speakers would say “overseas” or “abroad” — including landlocked destinations. Saying 海外旅行 (kaigai ryokou) means an international trip regardless of whether you cross an actual ocean. Also note that 海 alone is read うみ, but in compound words the reading can shift: 海岸 (kaigan, coastline) keeps the うみ root sound, while 海外 (kaigai) and 海産物 (kaisanbutsu, seafood products) use the on-reading かい.
海 is built from two components: the left side 氵 (sanzui), the three-dot water radical that appears in dozens of water-related kanji such as 川 (river) and 泳 (swim), and the right side 毎 (mai), which contributes the phonetic element and also carries a sense of “every” or “each time” — echoing the sea’s endless, repeating waves. Together the character visually and semantically signals a large body of water.
Everyday use
今年の夏は家族で海に泳ぎに行きました。
Kotoshi no natsu wa kazoku de umi ni oyogi ni ikimashita.
This summer, we went swimming in the sea with the family.
Casual / Social Media
夕暮れの海がきれいすぎて、思わず写真を撮ってしまった。
Yuugure no umi ga kirei sugite, omowazu shashin wo totte shimatta.
The sea at dusk was so beautiful that I couldn’t help snapping a photo.
Formal / Cultural context
海の日は、海の恩恵に感謝し、海洋国日本の繁栄を願う国民の祝日です。
Umi no Hi wa, umi no onkei ni kansha shi, kaiyou-koku Nihon no han’ei wo negau kokumin no shukujitsu desu.
Marine Day is a national holiday for giving thanks to the blessings of the sea and wishing for the prosperity of Japan as a maritime nation.
Japan’s relationship with 海 goes far beyond recreation. As an archipelago, the country has depended on the sea for protein for millennia — fish, shellfish, seaweed, and sea urchin form the backbone of Japanese cuisine. Fishing villages (漁村, gyoson) developed their own dialects, festivals, and Shinto shrines dedicated to sea deities (海神, watatsumi), and many coastal communities still perform purification rituals at the ocean’s edge at New Year.
Every third Monday of July, Japan observes 海の日 (Umi no Hi), Marine Day — one of the few public holidays in the world explicitly dedicated to the ocean. Established as a national holiday in 1996, it originally marked the date in 1876 when the Meiji Emperor returned by ship to Yokohama after a voyage around Tohoku. Around the same time, coastal towns hold their 海開き (umibira ki), the formal “opening of the sea” ceremony that signals beaches are safe and lifeguards are on duty for the summer swimming season.