
The larger kid is part of the yakuza I guess and he is getting sick of the other guy having fun watching Maria kill their group and just playing a mental game with her. So he wants his yakuza group to kill his "friend" and Maria on a school trip they're about to go on (guess they attempted once before and messed up the game the "friend" had planned). But the "friend" is already aware it's the large kid acting on his own and ruining his fun so he is planning to kill him on this trip (and ofc Maria will probably try killing one of them also for her plan). Basically we're probably getting into the last stretch of the manga here and we're going to see them all trying to kill one another on this trip
I love that I don’t know what’s happening!