Kuudere

A kuudere is cool, calm, and emotionally detached on the outside—but secretly cares deeply. These icy waifus don’t wear their heart on their sleeve, but when they finally show their emotions, it hits like a truck. Think Rei Ayanami from Evangelion. A fan favorite for stoic types who want to crack the code and unlock emotional fireworks.

Also see tsundere, yandere, etc.