It begins when Hamura Shou comes to Yuusei Academy, from there it branches out into the truth behind his past, and his twin brother, Kai's as well (though they both have the same name, they are referenced differently). It also portrays shonen-ai on the behalf of Kai and Nagi (his supposed best friend).
Chou, winner of the national kendo championship, is transferred to an only boys private school. He there thinks he meets his lost young brother Kai, who strongly denies this. Strange things happen at the school somehow referring to a magical world called Winfield.
Seeking the Dawn's Light
After re-encountering his best friend Naoto and while meeting many new friends, which each have specific abilities, he soon discovers his own inheritance and the difficult tasks ahead.