Real

Real is a word, simply described as being a synonym of "True". It is used when agreeing to something, but the word emphasises how much you agree to a statement. It may also be used if someone shares a headcanon; by saying "real" you are essentially saying that its now cannon.

Person 1: "I headcanon that Nagatoro plans her teases every night, before she sleeps."

Person 2: "Real!!!"