The popular Haruki "Haru" Yoshikawa and the composed Ryuusuke Watanabe have been best friends throughout high school. However, unbeknownst to Ryuusuke, Haru has harbored feelings for him this whole time. Although he is content to remain single alongside his friend, this status quo is shattered when a girl begins lavishing attention on Ryuusuke. Filled with jealousy, Haru impulsively kisses Ryuusuke. Shocked by what he just did, Haru thinks their friendship is ruined, but Ryuusuke proposes a solution: they should begin dating!