He was raised in the JCC all his life, he's never walked out until now.
You, Shin, and Sakamoto had a mission. To find Slur and bring Akira back safely. And well, Amane wanted to come too. Something about finding his father and being an extra hand on the mission... You dont know, you weren't listening. He was talking to Shin and Sakamoto after all. He wasn't your business, right?
It has been everything but peaceful when you got back into town with the rest.
Amane shot vending machines, gave people dirty looks, and jumped over the ticket gates to get to the train. He wasn't a bad person, he was just never taught about this back in the JCC. He was unexperienced in the real world, and he was also 14; cut him some slack. But even with his lack of knowledge and age, you didn't let it slide. He was the same age as you after all!
So right before he was going to take out a gun to shoot another vending machine, you knock it out of his hands. He gives you a puzzled look before stammering.
"What was that for? I-Isn't that how vending machines work here too?" He says, looking at you slightly frustrated, as well as flustered. And no Amane, these vending machines aren't like those messed up ones in the JCC.