High school student Aoi Aioi lives with her elder sister, Akane, after a tragic accident took their parents away 13 years ago. Because Akane has since been taking care of her single-handedly, Aoi wants to move to Tokyo after her graduation to relieve her sister's burden and pursue a musical career, inspired by Akane's ex-boyfriend Shinnosuke "Shinno" Kanamuro. Shinno was part of a band until he left for Tokyo to become a professional guitarist after the sisters' parents passed away, and he was never to be seen again.

One afternoon, while Aoi practices her bass in a guest house, she gets startled by the 18-year-old version of Shinno from 13 years ago! As if by coincidence, the current 31-year-old Shinno also returns to the town, but he has changed drastically. There are now two Shinno's in existence, but why is the Shinno from the past present?

Sora no Aosa wo Shiru Hito yo revolves around these four individuals as they confront their inner feelings toward each other and make decisions that will affect their lives from here on out.

[Written by MAL Rewrite]

Akutsu Masatora is a demon who has infiltrated a high school in the human world. His goal is to find candidates to aid Hell in the fight against their natural enemies, the angels of Heaven. Assigned a seat next to Lily Amane, another student who transferred here not long ago, Akutsu falls prey to her beauty and decides to recruit her to his cause. But there's more to Lily than meets the eye, and Akutsu not only finds himself an accomplice to one of the very enemies he is supposed to defeat, but he also might have developed feelings for her.

There is only one person that high school student Saito Houjou truly cannot stand—and that is his temperamental classmate, Akane Sakuramori. The two have always been on bad terms; their contrasting views and personalities only lead to endless fighting. However, everything changes when Saito's grandfather and Akane's grandmother arrange a sudden meeting and insist that the two get married! Walking down the aisle is the last thing Saito and Akane want, but they are quickly coerced into accepting the ridiculous plan and soon move into a shared house as husband and wife. Although Saito and Akane despise each other, navigating life together under the same roof may just turn their bitter hatred into everlasting love.

Mysteria Academy is a prestigious magic school that teaches magic without discrimination to the three factions (men, gods, demons), who usually are engaged in battle with each other. Two of the academy's students are Anne, a princess and honor student, and Grea, a princess born from a dragon and a human. (Source: ANN)