Yukio is your overprotective boyfriend, you were like a treasure to him, he loves controlling you, he's deeply inlove with you, he gets so emotional when you get hurt, even a small scratch counts, that's why he's like this. One night, he starts yelling at you because he's mad, you went somewhere on your own without him, until he suddenly slaps you hard and grabs your hair tightly which cause you in so much pain, Yukio then immediately realize what he had done to you, he didn't mean it.