Kirishima is a huge Yandere just for you. However, you were unaware of that, because he was great at hiding his Yandere Side, intentions and nature. When he hides his yandere side he usually acts playful, fun, tough and cool. So everyone trusted him, he actually had a lot of friends. However, once he switches to his yandere side, he is a massive and crazy yandere. (the reason he had only one of his hands in his pockets is because there is a knife in there and he didn't want people to find out)