An ogre or demon (oni) — a supernatural creature often depicted in Japanese folklore with horns and fangs.
日本の昔話に登場する鬼は赤い肌で角を持つことが多い。
Ogres that appear in Japanese folktales are often shown with red skin and horns.
節分には鬼を追い払うために豆まきをする。
At Setsubun people throw beans to drive away demons (oni).
山奥に住む鬼の伝説が残っている。
There remains a legend of an ogre living deep in the mountains.
The spirit of a deceased person — especially a restless soul lingering due to resentment or regret (older usage).
戦で亡くなった者の鬼を慰める儀式が行われた。
A ceremony was held to appease the spirits (oni) of those who died in battle.
村の古い伝承では、夜に彷徨う鬼が出ると言われる。
In the village's old lore, it is said that spirits of the dead wander at night.
An ogre-like person — used figuratively for someone fierce, relentless, or merciless.
彼女は鬼のように仕事をこなして、チームを引っ張った。
She worked like a demon and led the team.
あの先生は鬼だと言われるほど厳しい。
That teacher is said to be an 'oni' because he is so strict.
In games like tag or hide-and-seek, 'oni' refers to the person who is 'it' (the chaser).
じゃんけんで鬼を決めて、鬼がみんなを追いかけた。
They decided who would be 'it' for tag by rock-paper-scissors, and the 'oni' chased everyone.
鬼になったら、一人ずつ捕まえるルールだ。
When you become 'it', the rule is to catch people one by one.
A classical astronomical name — one of the 28 mansions (a Chinese-derived constellation name).
古代の星座体系では、『鬼』は二十八宿の一つとされた。
In ancient star systems, 'Ki' (鬼) was considered one of the 28 mansions.
A slangy prefix used to mean 'very' or 'extremely' (e.g., 鬼忙しい = extremely busy). Used colloquially for emphasis.
昨日は鬼忙しくて、夕飯を作る時間もなかった。
I was insanely busy yesterday and didn't even have time to make dinner.
そのゲーム、鬼おもしろいよ！ぜひやってみて。
That game is super fun! You should try it.