safebooruhttps://safebooru.org/index.php?page=atom&tags=1boy animal arms up bird black hair blue background blue necktie bokuto koutarou book bottle calculus chengongzi123 clenched teeth closed eyes clutching head collared jacket collared shirt cropped torso english commentary facing viewer furrowed brow geometry grey hair grey jacket haikyuu!! highres jacket long sleeves male focus math multicolored hair necktie owl pencil ruler shirt short hair simple background streaked hair striped necktie teeth thick eyebrows trigonometry very short hair water bottle white shirt2024-05-17T18:50:02Zsafebooru