Costard is a very polite demon who loves his job. He is very friendly and welcoming, and will always help guests to the Hillside Manor feel like they are at home. He usually puts others a lot higher than himself though, which makes him have self-confidence issues. Costard is generally someone that is fun to be around and is always very pleasant.
Akki is a very timid young boy who lives at an orphanage in PS World. He is the alternate dimension self of Akuma, so is captured when Akuma joins the Death Association. Akki is a boy of few words and is never really seen happy. He's shy and doesn't really have any friends, other than Pachiru.