LESSON NOTES · レッスンノート

N5Lesson notes · Oct 4, 2026

Back in Japanese: 背中せなか (せなか), 腰こし, 後うしろ, 戻もどる, and 背中せなかを押おす

The body part "back" in Japanese is 背中せなか (せなか). Lower back pain is 腰こしが痛いたい (こしがいたい), because the lower back is 腰こし. "Back" as a direction is 後うしろ (うしろ), "to come back" is 戻もどる (もどる), and the back side of a paper is 裏うら (うら). The idiom 背中せなかを押おす means to encourage someone.

The English word "back" does a lot of jobs, and Japanese splits it into several words. This post sorts them out, starting with the body and moving to direction and movement.

How do you say "back" (body part) in Japanese?

What does 背中せなか mean?

背中せなか (せなか) is your back, from the shoulders down to the middle of the back.

背中せなかがかゆい。 — My back is itchy. (casual) 背中せなかを洗あらってあげる。 — I'll wash your back for you. (casual)

What is 腰こし?

腰こし (こし) is the lower back and hips. Most "back pain" in Japanese is 腰痛ようつう (ようつう) or 腰こしが痛いたい.

重おもいものを持もって腰こしを痛いためた。 — I hurt my lower back lifting something heavy. (casual)

For clinic words, see how to say sick in Japanese.

What is the difference between 背中せなか and 腰こし?

背中せなか is the upper and middle back. 腰こし is the lower back. If you point to your lower back and say 背中せなか, Japanese listeners may picture the wrong spot.

How do you say "back" as a direction?

後うしろ (うしろ) is behind or the back of something.

後うしろの席せきに座すわった。 — I sat in the back seat. (casual) 後うしろを見みて! — Look behind you! (casual)

How do you say "come back"?

戻もどる (もどる) is to go back or return to a place. 帰かえる (かえる) is to go home.

すぐ戻もどります。 — I'll be right back. (polite) 席せきに戻もどってください。 — Please go back to your seat. (polite)

What is 裏うら?

裏うら (うら) is the back or reverse side: of paper, a coin, or a building.

紙かみの裏うらに書かいてください。 — Please write on the back of the paper. (polite)

Word Reading Meaning
背中せなか せなか back (body)
腰こし こし lower back
腰痛ようつう ようつう lower back pain
後うしろ うしろ behind, back
戻もどる もどる to come back
裏うら うら back side
背中せなかを押おす せなかをおす to encourage
背せを向むける せをむける to turn one's back

What does 背中せなかを押おす mean?

背中せなかを押おす, "push someone's back", means to encourage them to take a step they were afraid of.

友ともだちの言葉ことばが背中せなかを押おしてくれた。 — My friend's words gave me the push I needed. (casual)

背中せなかを押おす is a body-part idiom you can guess from the picture, like 手てを貸かす, "lend a hand", and Japanese idioms collects more of the family, such as 耳みみが痛いたい, "ears hurt", for a criticism that hits home.

For courage words, see courage in Japanese.

What does 背せを向むける mean?

背せを向むける, "turn your back", means to ignore or reject something.

問題もんだいに背せを向むけてはいけない。 — You shouldn't turn your back on the problem. (written style)

What about "back" in time?

For "back then", Japanese uses あの頃ころ (あのころ) or 昔むかし (むかし). For "a few days back", use 数日前すうじつまえ.

あの頃ころは毎日まいにち楽たのしかった。 — Back then, every day was fun. (casual)

What about the back of a building or a hidden side?

裏うら also means the hidden side of things. 裏口うらぐち (うらぐち) is a back door, 裏話うらばなし (うらばなし) is a behind-the-scenes story, and 裏表うらおもてがない describes an honest person with no hidden side.

裏口うらぐちから入はいってください。 — Please come in through the back door. (polite) 彼女かのじょは裏表うらおもてがない人ひとだ。 — She's the same person on the inside and outside. (casual)

The pair 表おもて (おもて, front) and 裏うら (うら, back) shows up everywhere, from coin tosses to the two halves of a baseball inning. Learning them together makes both easier to remember.

Common mistakes

  • Saying 背中せなかが痛いたい for lower back pain. Use 腰こしが痛いたい.
  • Using 後うしろ for "come back". Use 戻もどる.
  • Using 戻もどる for going home. 帰かえる is usual.
  • Saying 後うしろの紙かみ for the back of a page. Use 裏うら.
  • Taking 背中せなかを押おす as a push. It means encouragement.

Practice

Try each answer before opening it. Questions 1 and 2 are a pair: the back and the lower back.

1. Say "My back is itchy."

Show answer

背中せなかがかゆい。 — 背中せなか.

2. Say "I hurt my lower back lifting something heavy."

Show answer

重おもいものを持もって腰こしを痛いためた。 — 腰こし. This is the pair to question 1.

3. Say "I sat in the back seat."

Show answer

後うしろの席せきに座すわった。 — 後うしろ.

4. Shout "Look behind you!"

Show answer

後うしろを見みて! — 後うしろ.

5. Say politely "I'll be right back."

Show answer

すぐ戻もどります。 — 戻もどる.

6. Ask someone politely to go back to their seat.

Show answer

席せきに戻もどってください。 — 戻もどる.

7. Ask someone politely to write on the back of the paper.

Show answer

紙かみの裏うらに書かいてください。 — 裏うら.

8. Say "My friend's words gave me the push I needed."

Show answer

友ともだちの言葉ことばが背中せなかを押おしてくれた。 — 背中せなかを押おす.

9. Say "You shouldn't turn your back on the problem."

Show answer

問題もんだいに背せを向むけてはいけない。 — 背せを向むける.

10. Say "Back then, every day was fun."

Show answer

あの頃ころは毎日まいにち楽たのしかった。 — あの頃ころ.

A trial lesson is a good place to tell me who has encouraged you in your studies (背中せなかを押おす) and what hurts in your 背中せなか or 腰こし, using the right word for each.

FAQ

How do you say "back" (body part) in Japanese? 背中せなか (せなか).

How do you say "lower back pain"? 腰こしが痛いたい, or 腰痛ようつう.

How do you say "behind"? 後うしろ (うしろ).

How do you say "I'll be right back"? すぐ戻もどります.

How do you say "the back of the paper"? 紙かみの裏うら.

What does 背中せなかを押おす mean? To encourage someone.

Vocabulary from this article

Tap the block to select all of it, then copy. In Anki: File → Import, note type Basic, separator Tab — the first column becomes the front, the second the back.

背中	せなか — back (body)
腰	こし — lower back
腰痛	ようつう — lower back pain
後ろ	うしろ — behind
戻る	もどる — to come back
裏	うら — back side
背中を押す	せなかをおす — to encourage
背を向ける	せをむける — to turn one's back
あの頃	あのころ — back then
かゆい	かゆい — itchy
裏口	うらぐち — back door
裏表がない	うらおもてがない — honest, no hidden side

I'm Yuuki, a Japanese teacher based in Tokyo. I've taught on italki as a Top 1% teacher and watched over 1,500 anime. 背中せなかを押おす is one of my favorite phrases, because a small word from a teacher or friend really can be the push someone needs to keep studying. For practice with feedback, Book a trial lesson · $13, or try the Japanese practice exercises first.

Sources: the author's own lessons and standard reference dictionaries.

More drills like the ones above, plus a timed JLPT-style mock test: Practice · N5 · Read something at this level: JLPT N5 stories with audio

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