Japanese Words for Sleep: How to Say “Sleep” in Japanese & Sleep Culture

Hello, I’m Kodak.

How do you say “sleep” in Japanese?

When you check a dictionary, you may find several answers:

Japanese also has words for a daytime nap, accidental dozing, deep sleep, light sleep, sleeping too late, and many other sleep-related situations.

How Do You Say “Sleep” in Japanese?

The best Japanese translation depends on the grammar and situation.

1. 寝る (Neru): To Sleep, Go to Bed, or Lie Down

寝ねる is the basic everyday Japanese sleep verb.

毎晩11時に寝ます。
Maiban jūichi-ji ni nemasu.
I go to bed at 11 every night.

昨日は8時間寝た。
Kinō wa hachi-jikan neta.
I slept for eight hours yesterday.

疲れたから、少し寝る。
Tsukareta kara, sukoshi neru.
I’m tired, so I’m going to sleep for a while.

Because 寝る can also mean to lie down, context does not always guarantee that the person is unconscious.

ベッドで寝ながら本を読んでいる。
Beddo de nenagara hon o yonde iru.
I am reading a book while lying in bed.

2. 眠る (Nemuru): To Sleep or Be Asleep

眠ねむる focuses more directly on entering or remaining in the state of sleep.

赤ちゃんが静かに眠っている。
Akachan ga shizuka ni nemutte iru.
The baby is sleeping peacefully.

昨夜はよく眠れなかった。
Sakuya wa yoku nemurenakatta.
I could not sleep well last night.

この土地には貴重な資源が眠っている。
Kono tochi ni wa kichō na shigen ga nemutte iru.
Valuable resources lie hidden in this land.

In the final example, the resources are not literally sleeping. 眠る can describe something remaining inactive, unused, or undiscovered.

3. 睡眠 (Suimin): “Sleep” as a Formal Noun

睡眠すいみん is the standard formal noun for sleep.

It is common in medicine, health advice, research, news, and serious discussions about sleep habits.

健康のためには十分な睡眠が必要です。
Kenkō no tame ni wa jūbun na suimin ga hitsuyō desu.
Sufficient sleep is necessary for good health.

睡眠時間を記録しています。
Suimin jikan o kiroku shite imasu.
I am recording my sleep duration.

4. 眠り (Nemuri): Sleep, Slumber, or the State of Sleeping

眠ねむり is a noun formed from 眠る.

It can sound more personal, expressive, or literary than 睡眠.

赤ちゃんは深い眠りについている。
Akachan wa fukai nemuri ni tsuite iru.
The baby is in a deep sleep.

雨の音を聞きながら眠りについた。
Ame no oto o kikinagara nemuri ni tsuita.
I fell asleep while listening to the rain.

5. 眠い (Nemui): “Sleepy”

眠ねむい is an i-adjective meaning sleepy.

6. 眠気 (Nemuke): Sleepiness or Drowsiness

眠気ねむけ is a noun meaning sleepiness or drowsiness.

急に眠気が襲ってきた。
Kyū ni nemuke ga osotte kita.
A sudden wave of sleepiness came over me.

コーヒーを飲んで眠気を覚ました。
Kōhī o nonde nemuke o samashita.
I drank coffee to wake myself up.

この薬は眠気を引き起こすことがあります。
Kono kusuri wa nemuke o hikiokosu koto ga arimasu.
This medicine may cause drowsiness.

7. 昼寝 (Hirune): A Daytime Nap

昼寝ひるね means a nap taken during the daytime.

昼ご飯のあと、30分昼寝した。
Hirugohan no ato, sanjup-pun hirune shita.
I took a 30-minute nap after lunch.

赤ちゃんはお昼寝中です。
Akachan wa ohirune-chū desu.
The baby is taking a nap.

The softer form お昼寝 (ohirune) is especially common when talking about children, babies, and pets.

For a detailed explanation, see What Does Hirune Mean? How to Say “Nap” in Japanese.

8. 居眠り (Inemuri): Dozing While Sitting or Present

居眠いねむり means dozing while sitting or remaining in a place intended for another activity.

授業中に居眠りして、先生に注意された。
Jugyō-chū ni inemuri shite, sensei ni chūi sareta.
I dozed off during class and was warned by the teacher.

電車で居眠りして、駅を乗り過ごした。
Densha de inemuri shite, eki o norisugoshita.
I dozed off on the train and missed my stop.

9. うたた寝 (Utatane): An Unplanned Light Sleep

うたた寝 means drifting unintentionally into a light sleep, often while relaxing.

テレビを見ながら、うたた寝してしまった。
Terebi o minagara, utatane shite shimatta.
I dozed off while watching television.

10. 仮眠 (Kamin): A Short Sleep for Recovery

仮眠かみん means a short, temporary sleep taken for practical recovery.

It is often used for drivers, night-shift workers, travelers, and people resting between tasks.

運転する前に、少し仮眠を取った。
Unten suru mae ni, sukoshi kamin o totta.
I took a short nap before driving.

夜勤の休憩中に仮眠した。
Yakin no kyūkei-chū ni kamin shita.
I took a short sleep during my night-shift break.

11. 熟睡 (Jukusui): Deep Sleep

熟睡じゅくすい means deep sleep or to sleep deeply.

昨夜は久しぶりに熟睡できた。
Sakuya wa hisashiburi ni jukusui dekita.
I was able to sleep deeply for the first time in a while.

熟睡 sounds somewhat more objective or formal than the expressive adverb ぐっすり.

12. ぐっすり (Gussuri): Sleeping Soundly

ぐっすり is a Japanese mimetic adverb describing deep, sound, and uninterrupted sleep.

疲れていたので、朝までぐっすり眠った。
Tsukarete ita node, asa made gussuri nemutta.
I was tired, so I slept soundly until morning.

For its pronunciation, grammar, and debated “good sleep” folk etymology, see What Does Gussuri Mean? Japanese Sleep Onomatopoeia Explained.

13. すやすや (Suyasuya): Sleeping Peacefully

すやすや describes someone sleeping quietly, peacefully, and comfortably.

赤ちゃんがすやすや眠っている。
Akachan ga suyasuya nemutte iru.
The baby is sleeping peacefully.

14. うとうと (Utouto): Dozing Lightly

うとうと describes light sleep or drifting in and out of sleep.

暖かい部屋でうとうとしていた。
Atatakai heya de utouto shite ita.
I was dozing in the warm room.

15. 寝不足 (Nebusoku): Not Getting Enough Sleep

寝不足ねぶそく means not getting enough sleep.

昨日は寝不足で、頭がぼんやりしている。
Kinō wa nebusoku de, atama ga bonyari shite iru.
I did not get enough sleep, so my head feels foggy.

最近、寝不足が続いている。
Saikin, nebusoku ga tsuzuite iru.
I have not been getting enough sleep lately.

16. 不眠 and 不眠症 (Fumin / Fuminshō)

不眠ふみん means sleeplessness or inability to sleep.

不眠症ふみんしょう is the medical term commonly translated as insomnia.

17. 二度寝 (Nidone): Going Back to Sleep

二度寝にどね means going back to sleep after waking up once.

目覚ましを止めて、二度寝してしまった。
Mezamashi o tomete, nidone shite shimatta.
I turned off the alarm and fell back asleep.

休日の二度寝は気持ちいい。
Kyūjitsu no nidone wa kimochi ii.
Going back to sleep on a day off feels great.

18. 寝坊 (Nebō): Oversleeping or a Late Riser

寝坊ねぼう means sleeping later than intended or failing to wake up on time.

寝坊して、電車に乗り遅れた。
Nebō shite, densha ni noriokureta.
I overslept and missed the train.

彼は朝寝坊だ。
Kare wa asanebō da.
He is a late riser.

Quick Guide to Japanese Sleep Words

Useful Japanese Bedtime Phrases

おやすみなさい: Good Night

Other Useful Expressions

Mini Conversations About Sleep

Conversation 1: Going to Bed

Conversation 2: A Bad Night’s Sleep

Conversation 3: Taking a Nap

Conversation 4: Oversleeping

Japanese Sleep Culture: Important Ideas and Misunderstandings

There is no single way that every person in Japan sleeps.

Housing, age, family structure, work schedule, health, and personal preference all matter. Some people use futons, others use Western-style beds, and many households combine different arrangements.

Futon and Floor Sleeping

A traditional Japanese sleeping arrangement uses a 布団 (futon) laid on a tatami floor.

Futons can be folded and stored during the day, allowing a traditional room to serve as a living or dining space during the day and a bedroom at night.

However, many people in modern Japan sleep on beds. Futon sleeping remains familiar, but it is not the only Japanese sleeping arrangement.

Family Co-Sleeping, Soine, and “Sleeping Like the Character 川”

Japanese parents and young children have often shared a bedroom or slept in nearby futons.

The word 添い寝 (soine) means sleeping beside someone, often a baby or child.

母親が赤ちゃんに添い寝している。
Hahaoya ga akachan ni soine shite iru.
The mother is sleeping beside the baby.

The expression 川の字に寝る (kawa no ji ni neru) describes three people lying side by side like the three vertical lines of the kanji 川.

Inemuri: Sleeping While Still Socially Present

One of the most internationally discussed parts of Japanese sleep culture is 居眠り (inemuri).

Anthropological research has described it as being mentally asleep while still physically present in a public or work situation.

A person may briefly close their eyes in a long meeting or doze on a train while remaining seated and ready to return to the situation.

Inemuri is therefore not a general rule that “Japanese employees are allowed to sleep at work.”

Japan’s Short-Sleep Problem

Popular articles sometimes romanticize Japanese people as hardworking enough to sleep anywhere. That image can hide a more serious issue: insufficient sleep.

Japan’s Ministry of Health, Labour and Welfare has identified short sleep as a public-health concern. Its current sleep guidance uses at least six hours as a general benchmark for adults while emphasizing that individual sleep needs vary.

The ministry also reported that roughly four in ten adults in the 2019 National Health and Nutrition Survey slept fewer than six hours per night.

Bathing Before Bed

Taking a bath in the evening is a familiar part of daily life in many Japanese households.

A warm bath is not uniquely Japanese, but it connects naturally with Japanese bathing culture and bedtime routines.

Japanese health guidance notes that bathing approximately one to two hours before bedtime can help the body release heat afterward and make falling asleep easier.

寝る前にお風呂に入る。
Neru mae ni ofuro ni hairu.
I take a bath before going to bed.

Early to Bed, Early to Rise: 早寝早起き

The set phrase 早寝早起はやねはやおき means going to bed early and waking up early.

健康のために早寝早起きを心がけている。
Kenkō no tame ni hayane hayaoki o kokorogakete iru.
I try to go to bed and wake up early for my health.

The phrase is commonly taught to children as part of a regular daily routine.

Common Beginner Mistakes

Mistake 1: Translating Every English “Sleep” as 睡眠

睡眠 is primarily a noun. Use 寝る or 眠る as the everyday verb.

Mistake 2: Using 眠る for “Go to Bed” Every Time

For an ordinary bedtime action, 寝る is usually the natural choice.

Mistake 3: Confusing 眠い and 眠る

Mistake 4: Treating Every Nap Word as Interchangeable

昼寝, 居眠り, うたた寝, and 仮眠 differ in timing, intention, and situation.

Mistake 5: Thinking Inemuri Means Sleeping at Work Is Always Accepted

Inemuri is an ordinary word for dozing while seated. Social tolerance depends on context, role, disruption, and workplace expectations.

Mistake 6: Calling One Bad Night “Insomnia”

Use 眠れなかった for an ordinary night when you could not sleep. 不眠症 is a medical term.

Mistake 7: Assuming All Japanese People Sleep on Futons

Futons are culturally familiar, but Western-style beds are also widely used.

FAQ: Sleep in Japanese

What is the main Japanese word for sleep?

Use 寝る (neru) as the basic everyday verb meaning “to sleep” or “to go to bed.” 睡眠 (suimin) is the formal noun “sleep.”

What is the difference between neru and nemuru?

Neru includes going to bed, lying down, and sleeping. Nemuru focuses more directly on entering or remaining in the sleeping state.

How do you say “I’m sleepy” in Japanese?

Say 眠い (nemui) casually or 眠いです (nemui desu) politely.

How do you say “Good night” in Japanese?

Say おやすみなさい (oyasuminasai) politely or おやすみ (oyasumi) casually.

What is the Japanese word for a nap?

昼寝 (hirune) is the ordinary word for a daytime nap. 仮眠 (kamin) is a short practical sleep, while 居眠り (inemuri) is dozing while seated.

What does gussuri mean?

ぐっすり means soundly or deeply when describing sleep, as in ぐっすり眠る, “to sleep soundly.”

What is the difference between gussuri and suyasuya?

Gussuri emphasizes deep sleep. Suyasuya emphasizes quiet, peaceful sleep.

What does nebusoku mean?

寝不足 (nebusoku) means not getting enough sleep or being sleep-deprived.

What is the difference between nidone and nebō?

二度寝 means going back to sleep after waking once. 寝坊 means waking later than intended or oversleeping.

Do Japanese people sleep at work?

Some brief public dozing is described as inemuri and may be tolerated in certain contexts. It is inaccurate to say that every Japanese workplace permits employees to sleep whenever they choose.

Do all Japanese people sleep on futons?

No. Futon sleeping remains familiar, but many people use Western-style beds or combine different types of bedding.

What is kawa no ji ni neru?

川の字に寝る means three people sleeping side by side like the three vertical lines of the kanji 川, often used to describe parents sleeping with a child between them.

Summary: Japanese Words for Sleep

Related Articles

• Neru vs Nemuru: What Is the Difference Between Japanese Sleep Verbs?
• What Does Inemuri Mean? Japan’s “Sleeping at Work” Culture Explained
• What Does Hirune Mean? How to Say “Nap” in Japanese
• What Does Gussuri Mean? Japanese Sleep Onomatopoeia Explained

References

• National Institute for Japanese Language and Linguistics: 寝る — meanings and sentence patterns for 寝る.
• National Institute for Japanese Language and Linguistics: 眠る — sleeping-state and figurative meanings of 眠る.
• National Institute for Japanese Language and Linguistics: Japanese Onomatopoeia — explanations of Japanese sound-symbolic and mimetic words.
• Ministry of Health, Labour and Welfare: Sleep Policy and Sleep Guide 2023.
• Ministry of Health, Labour and Welfare: Minutes on the Sleep Guide 2023 — adult sleep benchmark and national short-sleep figures.
• Ministry of Health, Labour and Welfare: Sleep Quality Guidance — sleep environment, bathing, and bedtime recommendations.
• Web Japan: Traditional Japanese Rooms — daytime use of rooms and laying out futons at night.
• Web Japan: Japanese Futon Bedding — shikibuton and kakebuton.
• Sleep Patterns of Japanese Preschool Children and Their Parents — bedroom sharing and parent–child sleep patterns.
• Infant Sleeping Arrangements and Cultural Values Among Contemporary Japanese Mothers — cultural and practical aspects of parent–child sleeping arrangements.
• Brigitte Steger: Social and Cultural Aspects of Inemuri.
• Kotobank: 川の字 — three people sleeping side by side like the kanji 川.
• Kotobank: 二度寝.
• Kotobank: 寝坊.