Morisaki Shun is a Course 1 student at First High School who made a rough first impression—he came across as pretty elitist on day one, throwing around insults toward Tatsuya and the other Course 2 students. He was really hung up on the whole "Blooms versus Weeds" hierarchy thing.
Things escalated when he tried to show off that superiority by nearly attacking Leo with magic, apparently wanting to prove a point about the gap between the two courses. His plan fell apart when Erika smashed his CAD with her baton before he could do any real damage.
Despite that rocky start, he ended up getting recruited to the Public Morals Committee alongside Tatsuya, making him one of two new members that year. It's one of those situations where someone's first impression doesn't necessarily define where they end up.
Content compiled by AnimeList.moe from publicly available sources.