Mecha-ude: mechanical arms (volume 1)

kita-kagami city is a pretty normal town… except that some people have gotten their hands on mecha-ude: powerful, sentient, mechanical beings that attach themselves to their human hosts and have awesome capabilities. when middle-school kid hikaru accidentally activates alma, a mecha-ude with no memory of its past, they must team up to uncover the mystery of alma’s identity and prevent the powerful mecha-ude from ending up in the wrong hands.