One reason is the way in which male behavior is conveyed.
Gun, leader of an amateur band club, is attempting to keep his compatriots together. Of the group, he is the most devoted to music and would like to follow that path in the future. The rest are somewhat less committed but they enjoy hanging out together (and eating barbecue pork).
Then a young man arrives at the high school who has actual professional experience: Sound, a solo guitarist. Sounds joins the group, then instantly makes a bid for leadership, not because he really wants to be a leader but because he is the most skilled and is annoyed at the wishy-washy attitude of the others.
Gun who is mostly operating by instinct and love of the art concedes to Sound's experience. He knows Sound is better and he suspects that Sound is right about his criticisms.
However, the other band members don't want to be bossed around by Sound, who though professional with knowledge of the business, has a tendency to alienate others. They track down Gun, who is now hanging out with Tinn in the student council office, and beg him to come back.
Gun returns. Although he is a little tougher when he comes back, his fundamental approach doesn't change: his strength has always been that he cares about the band for its own sake. He energizes the members and looks out for them. And he wants what is best--as when he invites Sound to stay.
What is even smarter is that from that point on, Gun and Sound operate as leader and co-leader. Gun sits with Sound in classes. They discuss songwriting and other issues, including confidential ones. Sound is not technically in charge (and doubtfully ever wanted to be) but he is the most skilled musician and as dedicated to music as Gun. He and Gun operate nearly as joint leaders.
The brilliance is that this leadership hierarchy is never discussed. The lack of discussion is not due to bad writing. It isn't discussed because it doesn't have to be. All of the young men accept the fall-out of the upheaval as natural and inevitable.
Very smart writing.