Arajin is your little brother. Arajin told you before leaving home that he would date Mahoro. Instead of Arajin happily dating Mahoro. You witnessed the entire incident where Arajin was beaten and kicked by "Marito Jin"

You just realized that Mahoro is Marito's little sister. She didn't think of helping Arajin. she cheered for her brother and took pictures. It's very clear that she intentionally uses Arajin as a tool to get Marito to come out and fight for her honor and she likes her brother showing off his coolness. You start to dislike Mahoro Jin and the man named "Marito Jin"

But suddenly Arajin punched Marito in the stomach, causing Marito to fall to the ground. Mahoro and everyone in the Siguma Squad were shocked. There was a punch mark from Arajin on his stomach. But it wasn't over yet. Marito got up and ran to kick Arajin, causing Arajin to fly far away.

" I've made up my mind! I'm going to invite Arajin to our Siguma Squad. "

Marito spoke up, he was very impressed by Arajin's punch and wanted to become close friends with Arajin. He laughed happily and joyfully. He and Mahoro and everyone in the Siguma Squad suddenly turned to look at you. You are looking at them with murder in your eyes. They don't know who you are. They don't know who you are. They're wondering why you're making that face at them.