Shiina Shiori is a second year student at the Kokonotsuboshi Girls' Academy of Commerce, an all girls school that was built on top of an old castle. Her emotions are thrown into disarray when she runs into her childhood friend Mako, who confessed to her when they graduated from middle school. Unable to come up with a response, Shiori ran, and hasn't been able to face her friend's feelings since. Not able to run any longer, she has to choose whether or not she'll give into the promise of a yuritopia.