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. 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. 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. (info from Furinkan.com)
His nickname is derived from his hairstyle ("kakugari (カクガリ)" means "crew cut"), he has a large build. He is the least used of the stormtroopers and he often seen with Chibi. He is also the one who beats up Chibi the most.
He is the Lord of the Crimson Realm to whom Shana is bound. He expresses his will through a divine vessel called the Cocytus, which (in Shana's case) takes the form of a pendant. He is also a father-like figure to Shana, as he is always aiding her in her in confusion. Alastor is considered to be the strongest of all Lords or Denizens, even comparable to a god in the Crimson Realm. But even so, he tries to keep the Denizens from consuming Power of Existence. Unlike other lords that have a Flame Haze, his contractor can perform a method called Tenpa Jyousai, which requires a lot of Power of Existence and will manifest him to the world to consume all Denizens around him. This method is his Flame Haze's last resort.
Mie happened to pick up medicines that an old man dropped. When he took the medicine, his figure disappeared. Soon he went to a public bath to peep, and began to molest. Then, he went to a woman school.
Lum (also referred to in English dubs as Lamù) is a beautiful Oni alien who is capable of flying and generating electrical shocks. She is extremely popular and is famous for ending her sentences with ~datcha (loosely translated as "yes?" or "you know?"). Except when in her school girl's uniform, she usually wears a sexy outfit consisting of a tiger-striped bikini and knee-high go-go boots. While generally good-natured, sweet, and innocent, Lum also has a very hot temper. Her dream in life is to live in a "Sweet Home with Darling" in which she keeps house and raises babies while Ataru works. Unfortunately, Lum's idea of "cooking" is to take very spicy ingredients like jalapenos, cayenne peppers, and Tabasco sauce and irradiate them with an alien energy bazooka until they carbonize into inedible, crystallized nuggets. As an alien she has access to many bizarre gadgets whose use she really doesn't understand all that well, leading to comedic results. Differences between human and "Invader" physiology also drive many stories, like the time Lum's horns begin to grow larger after she is bitten by a cow, or the time she becomes drunk by eating pickled plums. (Source: Wikipedia)
His nickname is derived from his height ("chibi" means "small" or "short"), he is a timid crybaby, speaks with a cracked voice, and is often beaten up by the rest of the Gang of Four. He is often together with Kakugari. He also has buck teeth like that of a beaver's (though his nameless Manga counterpart did not have this).