Jariten, known to everyone as "Ten" is Lum's little cousin. Ten is a bratty and smart-mouthed alien toddler. Like all oni, Ten has powers of his own. He can fly and breathe fire. But he is an inexperienced child so his flying is awkward and slow, and his fire breathing isn't always effective.
Ten is a child, but sure doesn't act his age. He has a certain level of adult intelligence which is quite shocking for someone still in diapers. One result of being precocious is that Ten only has eyes for older women. He once had a crush on Sakura as well as the woman who ran the flower shop, Kurama and a few others. Yet Ten is still essentially a child and quite naive. Around women he is usually cute and diminutive. When he's near men he's his usual self. Loud, pesky and often aggressive.
Ten came to earth to meet Lum's new husband but was disappointed at what he found. From the moment they've met, Ataru and Ten have been at each other's throats. Ataru bullies, Ten flames his head. Ataru tricks Ten and makes fun of him, and he makes fun of Ataru. A real brotherly relationship.
Because Ataru is such an idiot, Ten doesn't think he deserves Lum. Therefore he decides to live with them to keep an eye on Ataru. As for Ataru, he is jealous of a baby's ability to use cuteness to get close to girls but mostly he feels that Ten is a major nuisance. But with all of the constant fighting between them, the truth is that they have a lot in common. Later on in the series they learn to live with each other, even though the insults still fly. If you didn't know any better, by the way they act with each other you might get the impression that they were brothers.
Ten's parents are always busy so he never really got to spend much time with them and was instead raised by a robotic nanny. In a way his cousin Lum is the only consistent mother figure he has ever had in his life. She's his legal guardian and takes care of him almost as if he was her child.
If you notice that Ten's dialect is a little unusual in comparison with the other characters, that is because his speech is based on the stereotypical dialect of Osaka.
Notes about the name
Jari sort of means "brat" So calling him by his full name Jariten is the same thing as calling him "bratty Ten." Note that only guys ever call him by his full name.
Voice: Kazuko Sugiyama
Ten is played by Kazuko Sugiyama. She has played roles in Magical Taruruuto-kun and Gatchaman.