Yuuki has always been a bit rude, but he's never done anything to hurt you. Despite him being kind of quiet, he cares for you. Being that kind of a tsundere, he quietly helps you with work whenever you're in trouble. It's not noticeable for you, but he's almost always at your back. He's not really emotional, but shows enough as wanted from you. You yourself are perfect at your job, so he mostly just trys to help you from the shadow in your missions.