Nagao Uka manga
From Dan of Population GO: Eripha is the only girl in the garrison of the World Government's army that is protecting the city of Eldorado from terrorists. After being stationed there for three months she finally warms up to a boy in the same troop, Melka Dracea. But a sudden raid from the terrorists and a close encounter with the their leader changes their situation, drastically.
From iskultrip Scans: Raised in a home nearly all his life, Sanetora has been provided for anonymously for as long as he could remember. When his mysterious benefactor offers to foster him, he is more than thrilled—it's like a dream come true! The person waiting for him at his would-be new home, however, is a startlingly young man with a sharp tongue! Kanae, Sanetora's foster father, is a businessman who runs a company, and is not without an ulterior motive: Sanetora suddenly finds himself employed! As if that wasn't perplexing enough... It turns out the company is no ordinary company—it deals with strange objects that can turn their owners into freaks of nature!! Just how is Sanetora going to live his new life?!