Marechiyo Ōmaeda is a large man (almost twice the height of his captain, and just over four times her weight). He claims that he is plump, which is a sign of his good living and wealth. He has black hair, and wears the standard Shinigami robes with a large purple collar. He is often seen wearing expensive, personalized jewelry.
Ōmaeda is an arrogant and dull man. He is cowardly, loud, vain, elitist, snobbish, greedy and sluggish. However, he is exceedingly loyal to his captain to the point that he is willing to fight along with his captain against enemies much stronger than himself. His willingness to take an attack aimed at his captain, act as a temporary decoy and cut off Suì-Fēng's arm at her request shows that Marechiyo holds a great deal of loyalty to her. Despite his arrogance, Ōmaeda has shown himself to be deceptively sharp in combat enough to catch his opponents off-guard. Ōmaeda likes to eat fried rice crackers (abura senbei) wherever he is and his captain is known to beat him up when the crumbs from the crackers fall on her hair. However, he does not like fish.