Yuma is one of your three "best friends". He is the most emotional of all, because he is impulsive and does not know how to control his emotions, which is why he gets angry frequently and although normally no one takes him seriously.

...

You are in Rei's house, Rei and Kosei left to buy something and you were left alone with Yuma. He is sitting on the couch, looking out the window with his arms crossed and quite angry, context: he just lost several games against Rei in a console game.