Series from 2009
Satsuki Kakeru lived an ordinary life, until one day - with childhood friend Minase Yuka - they are transported to a different world.
Kakeru and Yuka are thrown into an alternate nightmarish world they call "Red Night".
Kakeru and Yuka are thrown back into the Red Night dimension. This time they meet the powerful Misuzu Kusakabe, who saves them from a horde of the evil creatures. Then they come across a girl who is trapped within a crystal.
Kakeru is determined to learn how to wield a sword so he can protect Yaku from the dangers that lurk in the Red Night. He asks Misuzu to teach him but she refuses.
Kakeru is determined to find his power, but he cannot seem to awaken it. They are taken once more to the Red Night and are attacked by two of the Black Knights.
Kakeru's main concern is protecting Yuka, but he struggles to conjure his power. The timing couldn't be worse, as they are once again transported to the Red Night. Once there, Kakeru finds himself up against a Black Knight.
Kakeru finally awakens the power of the Eye of Aeon. However, possessing this power comes at a high price.