1girl 3boys border_operator_uniform_(world_trigger) breast_pocket chess_piece collared_shirt gloves half_updo hand_on_own_chin hand_up holding indoors jacket kashio_yutaka kittaka_haya kurauchi_kazuki kuro_n314 long_hair long_sleeves looking_at_another looking_away looking_down looking_to_the_side monochrome multiple_boys necktie open_mouth ouji_kazuaki ouji_squad's_uniform parted_bangs playing_games pocket shirt short_hair smile stroking_own_chin sweatdrop table thinking uniform wall world_trigger