ないじゅうがいごう 内柔外剛 LinksSentence search for 内柔外剛Sentence search for ないじゅうがいごうKanji details for 内, 柔, 外 and 剛Edit in JMdict Noun1. tough on the outside but soft at heartYojijukugo (four character compound) Discussions Log in to talk about this word.