朱に交われば赤くなる

しゅにまじわればあかくなるshunimajiwarebaakakunaru

expression · godan verb

1. people will take on the characteristics of those who surround them
2. spend time with the wise and you will become wise, but the friends of fools will suffer
3. when mixing with vermillion, one becomes red

Study it in Yanamino