Gatekeepers

Some years into the future, a strange, unexplainable natural disaster has broken off a piece of the Japanese mainland. Known as the Lost Ground, it is now inhabited by people with Alters -- machine-like extensions of their own will. In order to keep the peace on the Lost Ground, the HOLY organization uses its own Alter capabilists to police the region. In the midst of the chaos is a young man named Kazuma, whose life will soon change forever as he discovers his hidden abilities, and how to wield them.

Guided by a star only they can see, a group of maidens known as HiMEs have begun to gather at Fuuka Academy. These young women have been endowed with dangerous supernatural powers that they can use to their heart's content, but there's a price: to wield them, they must put their most important thing on the line. Now, in the midst of school work and friendships, they find themselves caught in the midst of strange conspiracies seemingly related to the terrifying monsters that attack them. Is the power of the HiMEs strong enough to save themselves and the ones they love?

Some things in life are so bad that you'd like to pretend they're just a dream. Unfortunately for Kazuki, trying to save a strange girl from being brutally killed by monsters (and ending up dying instead) is an unfortunate reality. Out of pity, the girl replaces Kazuki's heart with an alchemy-based artifact known as Kakugane, so that he may live on. With this strange device, Kazuki gains the power of Busou Renkin -- Arms Alchemy; a power that will come in handy when monsters (and worse) begin to plague his town! Kazuki soon meets the girl from his “dream” (named Tokiko) in reality, and she tells Kazuki to get on with his life; but with his sister and friends in danger, that might not be possible. Besides, if Kazuki gives up the chance to show off just how manly he can be, how can he hope to win the heart of the alluring older-sister-like Tokiko?!