His surname is No, and he reportedly hates fruits and vegetables. His voice has started to crack. However, he does drink fruit juice because he says it tastes good. He wears a propeller hat and, quite rarely, is said to fly through the sky using it. He is 12 years old and has blood type A. Though very rare, he can be timid. He is even more likely to become timid in front of scary people. His height is unpredictable, and he weighs 49kg. He likes friends, desserts, cats, cell phones, and his propeller hat. He dislikes boomers, nagging, scary people, junk food, and popcorn.

She is 12 years old, female, and has no blood type... (literally, because she is a water human). Surprisingly, she is confident and mischievous. She hates boomers.

He is a 12-year-old boy. He has wings on his back and is nearly immortal. It is said he can use the power of a phoenix. He can control fire and tends to be blunt. He hates boomers.

He is a 12-year-old boy. He is the only alien among the Jamminz and is a veteran UFO pilot. He hates boomers.

He is a 12-year-old boy. He is the only one among the Jamminz who wears glasses. He is hot-tempered and frequently uses profanity and slang. He hates boomers.

She is 12 years old, exceptionally pretty, and has blood type A. She tends to be angry or dissatisfied with people she meets for the first time. Once she grows fond of someone, that anger and dissatisfaction completely disappear. She often transforms into a shark and creates portal-like puddles to swim through. Whether she likes someone or not, she has a prickly side. Her bite is powerful enough to crack bones. The tip of Jamshaki's tail is sharp, so one might occasionally get hurt by it.

(Male) His surname is Jam, and his name is said to be derived from 'Korean' and 'Jammin'. Jam-(min Ko)rian. He attends Taekwondo classes (and has been doing so for 4 years). He is 12 years old and, like No Jam-min, has blood type A and can be a little timid. Being called a 'noob' or a 'weakling' shocks him and leaves him traumatized; because of this, he very rarely loses his reason. If things get worse, he will bring out all sorts of weapons. He likes Taekwondo, friends, playgrounds, and sand. He dislikes provocation, criticism, ridicule, dark places, and pickled radish. He is a picky eater very occasionally, though it's not common. Although he is a red belt in Taekwondo, his skills are said to be incredible.

He is 67 years old with blood type A. He nags a lot and is a total boomer. He especially loves to say, "Back in my day..." He intentionally acts in a way that makes communication impossible. It is best not to call him bald; if you do, he will fly into a massive rage and might throw the Jamminz, or resort to violence, kidnapping, and verbal abuse.