Emiya Shirou

The protagonist of Fate/stay night… but that should go without saying.
He is a diligent, hardworking man, who loves things like cooking, cleaning, and sewing. Though he always denies it, saying that he simply has no choice but to do all those things himself, that's an obvious lie. He's destined to become a housekeeper.
His inborn butler spirit will reveal itself after Rin's true ending, when he gets a part-time job working in the mansion of Rin's rival. Wait, what?
Also, though he'll remain a failure of a magus to the bitter end, he'll achieve great things as a spellcaster.

Fate/side material: Fate Encyclopedia