CinnamonYuno
Familiars were established as other-worldly beings sent down from the heavens to guard and protect a child born with extraordinary talents ahead of them. Sons and daughters of nobles, priests, future war-lords, and millionaire businessmen all were born with a familiar.
Ryu hasn't had much luck in the familiar department- so far, all of his master's have met quick ends, not entirely his fault. Still, the gods aren't happy, and they punish him- by sending him down to be a familiar to a lowly orphan.
Yuno hasn't has the best luck, either. He's an orphan, quiet, small, and half-blind. Yet, he's been blessed by the presence of a familiar. He can't believe his luck, but he soon finds out exactly why the familiar was sent to him.
Both are unlikely partners, if not unwilling, but when a government scandal and mysterious assassinations start plaguing the nation, they're going to have to start getting along- their lives are hanging in the balance.