How to say "obsession" in Japanese

• 執念しゅうねんCommon
  nounObsession as relentless, implacable persistence: a fixation that will not let go, often tinged with rancor. Fits someone who pursues a goal or grudge for years without giving up.
• 強迫観念きょうはくかんねんCommon
  nounCovers obsession in the psychological sense: an intrusive idea that keeps recurring and cannot be dismissed, the kind of fixed thought discussed in mental-health contexts.
  下手へたに手てを動うごかすと気付きづかれてしまうという強迫きょうはく観念かんねんが俺おれを襲おそう。↗

  I was assailed by the stupid, but unshakeable, idea that if I was imprudent enough to move my hand I'd be noticed.
• 執着しゅうちゃくJLPT N1approx.Common
  noun, suru verb, intransitive verbIts core sense is attachment, so it fits 'obsession' when the idea is clinging to a person, thing, or belief and being unable to let go; emotional fixation rather than drive.
  彼かれは弁護士べんごしになれるという希望きぼうに執着しゅうちゃくしていた。↗

  He clung to the hope that he could be a lawyer.
• ノイローゼJLPT N1approx.Common
  nounSeldom the word you want for 'obsession': it really means a neurosis or nervous breakdown. Use it for the state of being mentally worn down, not for the fixation itself.
  本物ほんもののノイローゼの奴やつがノイローゼだなんて自称じしょうするのかね？↗

  Do you think real neurotics really go and call themselves such?
• 沼ぬまJLPT N1approx.Common
  noun, noun (suffix)Slang for being hooked on something or sucked in: a hobby, game, or fandom one is hopelessly deep into. The casual, self-mocking 'I'm obsessed' of everyday conversation.

Choose 執念 for relentless, grudge-tinged persistence, 強迫観念 for intrusive psychological obsessions, 執着 for attachment one cannot let go of, 「ノイローゼ」 for the resulting neurotic state, and slangy 沼 for being hooked on a hobby.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

• 執念しゅうねんtenacity
• 強迫観念きょうはくかんねんobsession
• 執着しゅうちゃくattachment
• ノイローゼneurosis
• こだわりobsession
• オブセッションobsession
• 沼ぬまobsession
• きちがいmania
• 強迫きょうはくobsession