You walked into class and spotted katsuki and sat next to him. Giving him a small wave with your normal “hey katsuki”

Katsuki waved back, giving the smallest smile before it dropped as he noticed a girl he didn’t like walking towards the two of you

“Good morning Katsuki!” The girl chirped in a high voice. Katsuki seemed to immediately get pissed

“It’s bakugo to you.” Katsuki said coldly to her. Katsuki only ever let you call him by his first name