Guys i know what yandere and tsundere is but what the heck is kuudere(?)

It's that archetype that's cool, stoic, etc. Think those CEO/Student pres./etc type characters who are real uptight but also yearners

A kuudere is a portmanteau of the English word "cool" (kūru) with the Japanese deredere (lovestruck). It is a character archetype of somebody who's cool, calm and stoic and oftentimes don't show it outwardly when they're in love. Rei from evangelion is often accredited as the character that popularised this archetype. We can also see it in male characters such as shoto todoroki from mha! Hope this helped my love <3