Oyuki is the queen of Neptune, which in the series is a frozen, snowy planet populated entirely by women, as most of the men have to go off-planet to find work. As a child she used to hang out with Lum, Ran, and Benten when they were all in grade school. She is clearly patterned after the yuki-onna (literally "snow woman") of Japanese folklore. As such, she has the power to control and create ice, snow, and extreme cold. Typically dressed in a long, elegant kimono, Oyuki is soft-spoken, regal in demeanor and very slow to show anger. However, once roused to actually display her abilities she proves to be the most powerful character in the series. Because of the wrath she displays when angered, Oyuki is the only person in the entire galaxy that Ran genuinely fears.
Touma Kazamatsuri is a glasses wearing bookworm, with short, messy dark hair. She dislikes her hair in the morning, as it is a bad bedhead. She also seems to have a connection with a hair elastic. Touma also has a collection of plushies, which sit on top of her bookshelf at home. She prefers to be by herself alone in a quiet place, preferably the library. She also dislikes P.E class. Although Touma is easily annoyed by Torako's interference and she seems to dislike Torako on the surface, she is actually a good friend of Torako's, and cares for her (though she tries not to show it). She and Torako made a promise of becoming mutual friends, when they made a visit to the Kamizono Academy and met each other by chance. Touma has an older sister which she often fights with.
Hattori Heiji is a high school detective from Osaka, titled Great Detective of the West. He came to Tokyo to test himself against Shinichi. Thanks to his detective skills, Heiji eventually figured out that Conan is the brains behind Mouri, and that Conan is in fact Shinichi. The two become good friends after that, working on cases together when the opportunity arises. Occasionally Heiji gets Conan into a tight spot by calling him Kudou in front of Ran, but thanks to his puns, everything always seems alright. Heiji has a strong Kansai accent and he can't seem to speak standard Japanese because his accent is so strong. Heiji is the son of the Osaka district police commissioner (a position at the top of the hierarchy), but Heiji prefers to get by on his own merits. Heiji gets his slightly dark skin from his grandfather. His childhood friend, Toyama Kazuha, has a budding, but denied romance going with him. In Detective Conan's 7th movie, it's revealed that Kazuha is apparently Heiji's first love, but Kazuha didn't know about it. (Source: Tanteikid.com)
Tooyama Kazuha is the childhood friend and romantic interest of Hattori Heiji. Their fathers work together at the Osaka Police station, where Kazuha's father, Tooyama Ginshirou is a subordinate and close friend of Heiji's father, Police Chief Hattori Heizou. At one time in their youth, Heiji had had the unfortunate idea of locking themselves together with a set of old handcuffs which had no key to unlock it; as a result they involuntarily had to spend time together even on some rather intimate occasions (i.e., bathroom visits) before the cuffs could be removed. As a reminder of this 'closeness' and for good luck, Kazuha fashioned two identical lucky charms, each incorporating a chain link from the cuffs, which she and Heiji have been wearing ever since. At some later point, Kazuha added a picture of Heiji into her own charm pouch. Kazuha has a hot temper and can be highly critical of people around her. She has been hinted to have a high level of intelligence, as she was able to deduce a dying message in an episode even more quickly than either Ran or Kogoro could (albeit with slight help from Heiji). Moreover, she is highly confrontational and unafraid to let others know of her dislike, even showed no hesitation or concern confronting Heiji in men's restroom. This trait leads to frequent shouting matches with Heiji, but it also allowed her and Ran to forge a strong friendship. She also has a marked belief in spirits, good-luck charms, and other superstitions. Right from her first experience, she displayed her belief in the importance of hers and Heiji's omamori, charms which Kazuha made to protect her and Heiji from harm. And indeed, during the same case, Heiji lent Conan his omamori, and the metal inside the charm stopped a knife blade that would have killed Conan. On subsequent cases, Kazuha is quick to attribute mysterious shadows and strange events to ghosts and other malignant spirits, which usually sends Ran into a panic as well, though she herself does not possess a morbid fear of ghosts as much as Ran does.
Lum's childhood friend and most loyal friend in the Galaxy. Her character is named after Shichifukujin Benzaiten (one of the Seven Lucky Gods), the Shinto goddess of knowledge, art, and beauty. This Benten is a "space biker chick" who wears a plate-mail bikini, sports a "butch" hair style, tears around the sky on a flying alien chopper, curses like a longshoreman, and carries a high-tech bazooka. She's sassy, smart and easy going. She's also has a good sense of humor and an even greater sense of honor. She's always willing to help Lum whenever she's gets in a tight spot. (Source: Wikipedia)
The principal of the high school that the cast attends.