na-adjective, noun
naivete; innocence; artlessness
Describes a pure, unspoiled, and childlike innocence, often implying a lack of worldly experience or guile. Frequently used in the phrase 天真爛漫 (てんしんらんまん).
彼女の天真爛漫な笑顔に心が和んだ。
Her innocent and artless smile was heartwarming.
彼の天真な性格は、時に無防備すぎるように見える。
His naive personality sometimes seems overly defenseless.
Composed of 天 (heaven, nature) and 真 (truth, reality), suggesting an innate, heaven-sent purity. The exact historical derivation is uncertain, but the compound is conventionally associated with natural, unadorned innocence.