Description:

Long ago, there existed two different groups of people. One had red blood and the other had blue blood. They co-existed peacefully, but eventually they started to hate each other and a war broke out. The massive red blood army initially overwhelmed the blue blood but with the help of new technology developed by Kodo, the prince of the blue blood, the blue bloods were victorious. The new technology, called the Haguruma, is a powerful robot type machinery capable of devastating destruction. As the red blood people were enslaved, Kodo saw what monstrosity his Haguruma was being used for. Helpless red blood people were being hunted down and murdered. Overwhelmed by guilt, Kodo rescued the refugee red bloods and refused to build any more machines. His father, the king, ordered him to be executed, but he barely escaped and now without a home, he must survive on his own. (Source: MangaHelpers)

Description:

Buso Renkin is the story of teenager Kazuki Muto, who dies trying to save a girl who was being attacked by an eerie monster. The next morning, however, Kazuki is left wondering whether it was all a dream. Lo and behold, the girl, the monster, and his death are all real! The girl, Tokiko Tsumura, was actually trying to slay the homunculus (a beast that can take the form of humans, but whose main source of food is people), but Kazuki got in her way. To revive Kazuki, Tokiko replaces his heart with a "kakugane," an alchemic device that allows him to summon a lance with which to fight the monsters. It turns out that Tokiko is a member of Renkin Kenshi (Alchemist Soldiers), an organization sworn to protect the world from the diabolical creatures. Soon, Kazuki joins Tokiko in her quest to terminate the sinister being that creates and controls the homunculus. (Source: Viz)