彼は見かけによらず純情な青年だ。
Despite his appearance, he is a pure-hearted young man.
弟は純情で、人の言うことをすぐに信じてしまう。
My younger brother is naive and readily believes whatever people tell him.
手を握られただけで赤くなるなんて、彼女は本当に純情だ。
She really is innocent, blushing just from having her hand held.