純真・純心|じゅんしんjunshin[0]heiban (flat)

1. na-adjective, nounpure; innocent; naive; unspoilt; pure-hearted; ingenuous
   彼女かのじょの純真じゅんしんげなそぶりは見みせかけで本物ほんものではない。↗

   Her air of innocence is apparent, not real.

• SynonymナイーブCasualColloquial loanword. In Japanese it mostly suggests a sensitive nature that is easily hurt, though it can also mean naive and simple; not a perfect match for 「純真」.
• Synonym純情じゅんじょうNeutralRefers to a pure heart or emotions, often in matters of love, as in 「純情な少年」. 「純真」 puts more weight on a clean, unstained mind.
• Synonym純粋じゅんすいNeutralMeans pure and sincere; it can describe substances with nothing mixed in as well as an honest heart, so its range is wider than 「純真」.
• Synonym無邪気むじゃきNeutralInnocent and free of any bad intent, typically like a child; it sounds more childlike than 「純真」.
• Synonym無垢むくWrittenA written word for spotless purity, usually in the set phrase 「純真無垢」; it stresses being completely unstained.
• Synonym清純せいじゅんWrittenWritten word for a pure, fresh quality, applied mostly to young women of innocent character.
• SynonymピュアCasualCasual loanword meaning pure. It has a light, trendy feel and turns up often in advertising and young people's speech.
• Synonym初々しいういういしいNeutralSuggests the fresh, green charm of the young or of beginners; it highlights endearing inexperience rather than purity of heart.
• Synonym純朴じゅんぼくNeutralSimple, honest and unpretentious; it can describe anyone, while 「純真」 stresses a heart that is clean and free of evil.
• Synonym無心むしんWrittenA written word for a mind free of distracting thoughts, absorbed in one thing, like a child lost in play.
• Synonym純じゅんCasualA one-character na-adjective used in speech, as in 「純な人」; it is simply a shorter, lighter alternative to 「純真」.
• Synonym純潔じゅんけつWrittenWritten word for purity or chastity. It stresses having no sexual experience or an unblemished moral record, a narrower sense than 「純真」.
• SynonymイノセントNeutralLoanword that leans toward guiltless or blameless rather than everyday innocence; rare in conversation, so it differs from 「純真」.
• Synonym天真爛漫てんしんらんまんWrittenA four-character idiom for bright, carefree, utterly unpretentious innocence; it has a written, literary flavour.
• Related清いきよいNeutralCovers clear water as well as a pure heart, with a literary tinge; its range is broader than 「純真」.
• Related清らかきよらかWrittenWritten word for something clear and pure, carrying a solemn, almost sacred nuance; used mostly of hearts or flowing water.
• RelatedすれてないCasualColloquial for someone not yet jaded; it stresses not being stained by the ways of the world, while 「純真」 leans toward written description.
• Related天衣無縫てんいむほうWrittenDescribes a natural, artless character with no trace of affectation; it also praises poetry or prose of effortless beauty.
• Related天真てんしんWrittenA written word for natural, unadorned innocence, rarely used on its own; it usually appears inside 「天真爛漫」.
• Antonym邪心じゃしんWrittenA written word for a twisted, wicked heart — the exact opposite of 「純真」, which denotes a heart clean and unstained.
• Antonym悪心あくしんWrittenA written word for the malicious intent to do wrong; it stands opposite to 「純真」, which implies no such dark thoughts.

「純真」 is for a clean, unstained heart, as in 「純真な子ども」. For childlike innocence pick 「無邪気」, for pure feelings often in love 「純情」, for pure as in unmixed or sincere 「純粋」. Written prose prefers 「純潔」 (chastity), 「無垢」 (spotless), 「清純」 (young women), 「清らか」, 「天真爛漫」 and 「天真」; casual speech uses 「ナイーブ」, 「ピュア」, 「すれてない」 or 「純」. 「清い」 covers water and heart, 「初々しい」 youthful greenness, 「純朴」 simple honesty, 「無心」 an absorbed mind, 「天衣無縫」 artless grace, 「イノセント」 blameless innocence. 「邪心」 and 「悪心」 are its written antonyms.

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

1. 心身しんしんの汚よごれていないこと。清きよらかなこと。