Hino Akiharu lost his parents when he was small and was adopted into his uncle's family. He didn't want to be a burden on his uncle's family and decides to enter a free boarding school as a butler, Hakureiryou high school. However, his delinquent boy-like appearance frightens the girls, who make up the majority of the students. Unable to get along with the classmates, Akiharu meets his childhood crush Saikyou Tomomi.

As she edges toward the end of her high school life, the energetic but generally clueless third-year Tamako Kitashirakawa has only one major concern: pulling off a stunning baton performance at the Usagiyama Marching Festival. But all too soon, she is confronted by the reality that all her friends have big plans for their futures; she, on the other hand, just operates with the moderate goal of continuing to work at her family's restaurant. Under the same brilliant sky, Mochizou Ooji intends to study at a university in Tokyo, leaving behind his family, friends, and most importantly, his first and only love Tamako. Unfortunately, the shy admirer cannot bring himself to declare his love, and Tamako is yet unaware that she is the source of such anguish. With time quickly running out, Mochizou must confess his feelings to Tamako soon, or his dream of romance will never be fulfilled. [Written by MAL Rewrite]

With a smirk, Oota disregards his single-digit test scores and searches for a new source of amusement. He is soon captivated by his classmate Kashiwada, a mysterious student who consistently wears a blank face. Oota conspires to break her placid demeanor through scares and mischievous schemes, though his tactics always seem to backfire. Oota is known as the class clown and is constantly disciplined by his teacher, who claims "his face gives it away." To no fault of his own, he lacks control of his emotions and facial expressions. Kashiwada, on the other hand, seems perpetually emotionless and unreadable—no one knows what she is thinking! Oota and Kashiwada are complete opposites, but that does not stop a unique relationship from developing between them. As they realize their feelings for each other, it raises an important question: do opposites really attract?

Many years ago, after the end of a bloody world war, mankind took shelter in six city-states that were peaceful and perfect... at least on the surface. However, Shion—an elite resident of the city-state No. 6—gained a new perspective on the world he lives in, thanks to a chance encounter with a mysterious boy, Nezumi. Nezumi turned out to be just one of many who lived in the desolate wasteland beyond the walls of the supposed utopia. But despite knowing that the other boy was a fugitive, Shion decided to take him in for the night and protect him, which resulted in drastic consequences: because of his actions, Shion and his mother lost their status as elites and were relocated elsewhere, and the darker side of the city began to make itself known. Now, a long time after their life-altering first meeting, Shion and Nezumi are finally brought together once again—the former elite and the boy on the run are about to embark on an adventure that will, in time, reveal the shattering secrets of No. 6. [Written by MAL Rewrite]