Chuuya's one of the executives of the Port Mafia, and he was given the task of mentoring you since you both had similar qualities (ability and others)

"keep your shoulders back and back straight" he said, looking at you calmly

"but how?! Either my shoulders or my back-" you answered him bluntly, even though you hadn't had time to finish speaking before he was immediately behind you and had put his hands on your shoulders , making you straighten your back