根性|こんじょうkonjou[1]atamadaka (head-high)

1. nounwillpower; guts; determination; grit; spirit
   セッティングは整ととのえておいたから、後あとはまーくんが根性こんじょう見みせなきゃダメだからね？↗

   I've set the stage so now you just have to show some guts, OK?
2. nouncharacter; nature; disposition; personality

• Synonym性格せいかくNeutralThe most widely used word for character or personality; neutral in tone, with none of the grit or determination that 「根性」 carries.
• Synonym性質せいしつNeutralNature or disposition, but also the properties of things; it reads as fairly objective description and lacks the grit sense of 「根性」.
• Synonym気質きしつNeutralTemperament: an innate personal makeup, or the shared spirit of a type of person, as in 「職人気質」. It lacks the grit sense of 「根性」.
• Synonym度胸どきょうNeutralCourage or nerve — the boldness to face things without flinching, not the perseverance to see things through that 「根性」 implies.
• Synonym性根しょうねNeutralOne's fundamental character, and also long-sustained perseverance — both senses close to 「根性」. Phrases like 「性根が腐る」 are derogatory.
• Synonym性せいWrittenNature or sex/gender, mostly in compounds; on its own it belongs to written/formal prose and says nothing about grit.
• Synonym意気いきWrittenZeal or drive, mostly in compounds like 「意気込み」 and 「意気投合」; on its own it belongs to written/formal prose.
• Synonym気概きがいNeutralBackbone and fighting spirit, stressing an unyielding attitude; close to the grit sense of 「根性」.
• Synonym天性てんせいNeutralOne's innate nature — the temperament one is born with; it says nothing about grit forged through later effort.
• Synonym気性きしょうNeutralOne's temper or disposition, focusing on whether it is fiery or mild, as in 「気性が荒い」.
• Synonym本性ほんしょうNeutralOne's true nature — the character hidden beneath the surface, as in 「本性を現す」.
• Synonym気骨きこつWrittenMoral backbone — holding to one's principles and refusing to yield; used in written/formal prose.
• Synonym真性しんせいWrittenUsed in written/formal prose for inborn nature; also 「真性の」 for something genuine. Close to the nature sense of 「根性」 but with no grit nuance.
• Synonym心根こころねNeutralThe nature deep in one's heart, used in praise or blame, as in 「心根が優しい」 and 「心根が卑しい」; no grit sense.
• SynonymガッツCasualA colloquial loanword for drive and fighting spirit, as in 「ガッツがある」; close to the grit sense of 「根性」 but with no character nuance.
• Synonym気立てきだてNeutralA person's disposition, judged by whether they are kind and good-natured, as in 「気立てがいい」. 「根性」 stresses grit and one's fundamental character.
• Synonym質しちNeutralThe collateral sense, read 「しち」, is unrelated to 「根性」; the listed 「たち」 means temperament, suggesting a reading mix-up in this entry.
• Synonym胆力たんりょくWrittenUsed in written/formal prose for courage and boldness, stressing fearlessness in the face of things.
• SynonymきっぷNeutralA hearty, open-hearted character, as in 「気っ風がいい」; the emphasis is on being straightforward and generous.
• Synonym胆気たんきWrittenA rare word in written/formal prose for courage and daring; in modern usage 「度胸」 is the usual choice.
• Synonym天資てんしWrittenA rare word in written/formal prose for natural endowment, stressing innate gifts.
• Related肝っ玉きもったまCasualA colloquial word for guts, as in 「肝っ玉が太い」; the emphasis is on being bold.
• Antonym無根性NeutralHaving no perseverance — the opposite of 「根性」 in its gritty, never-say-die sense.

Use 「根性」 for gritty perseverance or a person's fundamental character, as in 「根性がある」「根性を叩き直す」「島国根性」. For plain character or personality say 「性格」; for courage say 「度胸」; for backbone and fighting spirit say 「気概」; in colloquial speech, sheer grit is 「ガッツ」. Words like 「気立て」, 「気質」 and 「気性」 describe temperament without the grit nuance, while 「性根」 overlaps with 「根性」 in both senses.

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

1. 人間にんげんに本来ほんらい備そなわっている、善ぜんと悪あくを生み出うみだす力ちから。
2. 根本的こんぽんてきな性質せいしつ、性格せいかく。しょうね。こころね。
3. 困難こんなんに強つよい性質せいしつ、性格せいかく。忍耐力にんたいりょく。