also: まこころ
noun, noun which may take the genitive case particle 'no'
sincerity; true heart; devotion
A warm, genuine feeling from the heart; often used for selfless kindness, earnest effort, or heartfelt gifts. Can be used as a noun or with の to modify another noun.
彼の真心のこもった手紙に感動した。
I was moved by his heartfelt letter.
真心を込めて料理を作る。
I cook with sincerity.