Messiah: Code Edge

Mysterious, handsome young men working as spy-pairs for a secret agency, the Church, are forbidden to love anyone but their partners. If they're to survive—not only war, but the ghosts of their tragic pasts—they must rely on one another to be there...because each other is all they have. Follow Eiri, Haku, Soma, and Shusuke as they battle their inner demons with the help of their partners in this peek into the Messiah Project universe.

(Source: Kodansha USA)