In the Binfield Kingdom Chronicle, it is said that there was once a small, peaceful country called the Kingdom of Winfield, whose king and royal family possessed great white wings. Hamura Shou is newly enrolled at Yuusei Academy. After hearing about a student named Misonou Kai from the headmaster, Shou comes to believe that Kai is his younger twin brother, who he was separated from when he was younger. However, after a mysterious earthquake, Shou is suddenly carried into another world with two other students. It is in this new world that, after being attacked by a monster, Shou suddenly unleashes great, white wings.

Arisa, a 16-year-old high school girl, accidentally has an extreme fighting suit that her brother invented implanted in her body. It's a slightly embarrassing suit that makes her emit an H voice when she transforms. Moreover, from that day on, Arisa is forced against her will to fight a secret society of evil. Oh, I want to tell my feelings to Matsumoto-senpai, the man of my dreams, but only when I do so, I transform into an H battle suit. (Source: AllCinema, translated)

Touma Kusaka stands out from the rest of the Choshu Clan, as he does not share their anti-foreigner sentiment. After reuniting with Keiichirou Akizuki, a vassal of the Tokugawa family who once helped him escape from government authorities, the pair begin studying English in secret. As they continue to meet behind their feuding families' backs, romance between the two begins to bloom. But with war looming on the horizon between their respective clans, Kusaka and Akizuki's hope for a world where they can be together may never come to fruition if their obligations and bloodlines get in the way.

Maya, Kurusu, and Chelsea hit it off really well when trying to get revenge on Guardian Hearts for making them suffer. Maya and company thought that Guardian Hearts usually appears when Kazuya is getting along with a girl. Not knowing that Guardian Hearts is actually Hina, they leave her alone with Kazuya in an attempt to lure Guardian Hearts. (Source: AniDB)