noun
frankness; impulsiveness
Describes a personality that acts on immediate feelings without calculation; often used in the compound 直情径行 (acting on impulse).
彼は直情径行な性格で、思ったことをすぐ口にする。
He has a frank and impulsive personality, and immediately says what he thinks.
直情だけで動くと、後で後悔することもある。
If you act purely on impulse, you may regret it later.
Compound of 直 (direct, straight) and 情 (emotion, feeling). The exact historical derivation is uncertain, but the word has been used to describe an unmediated emotional nature.