Ryuuto Kashima is a gloomy high schooler. As part of a punishment game, he was forced to confess to Runa Shirakawa, a girl from the top of the school caste who was admired by everyone. They ended up going out for the unexpected reason of "Err, I'm free now so..." but Ryuuto ends up following and eavesdropping on Runa being confessed by a handsome soccer club member, and Runa bringing Ryuuto, whom she had just begun dating, to her own room as a matter of course. They have different friends and ways to have fun, and they are different in almost every way. Nonetheless, they begin to relate with each other after being surprised by their differences every day and accepting them.