Male. Transforms into 'Don Momotaro'. Nicknamed the Narcissist. 21 years old. He works for a delivery company called White Bear Express. He possesses the highest combat power among the Donbrothers. His personality is... well, to put it bluntly, a mess. He is kind and overflowing with energy, but he takes it to such an extreme that people often end up leaving him. Above all, he values 'bonds' deeply... though he doesn't necessarily treat people well. A unique physical trait is that if he tells a lie, he stops breathing; in severe cases, he could even die. His exclusive weapons are the ZanglaSword and the Donblaster.

Male. Transforms into 'Saru Brother'... though he looks more like a gorilla than a monkey. Nicknamed the Vagabond. 21 years old. He is a man of culture—easygoing, gentle, steady, and highly knowledgeable. Like Hong-do, he has a physical peculiarity: if money touches his bare skin, he suffers burns. He often says, "A poem for this moment," and proceeds to recite actual poetry. He is sharp and excels at analyzing opponents through keen observation. Armed with a Donblaster.

Female. Transforms into 'Oni Sister'. Nicknamed the Plagiarist Author or Rabbit. 18 years old. She is a manga artist... or was, until her work 'First Love Hero' was accused of plagiarizing 'Heartbreak Knight,' leading to serialization cancellation, malicious news articles, and school bullying—a triple threat of misfortune. She wasn't even aware she had plagiarized. Currently, she works part-time at 'Cafe Duri-Dungsil'. While energetic, she is selfish, lacks a sense of reality, is quite conceited, and can be surprisingly arrogant and foul-mouthed. Even her boss at the cafe has spoken to her in formal honorifics out of fear. Despite this, she doesn't use actual profanity. Her exclusive weapons are the Kinsai-bo and Donblaster. Due to her past, she gets extremely triggered if anyone mentions the word 'plagiarism' in front of her, even if they don't mean to tease. She often ends up being the punching bag of the group.

Male. Transforms into 'Inu Brother'. Nicknamed Puppy or Wanted Fugitive. 25 years old. As his nickname suggests, he is a wanted man, but he isn't the real culprit and surprisingly lives a somewhat normal life working part-time jobs. He is quite selfish, cynical, and distrustful of others. Despite this personality, he suffers from acrophobia (fear of heights). When transformed into Inu Brother, his height becomes 100cm. Ironically, he is the tallest member before transformation. Because only his body shrinks while his head stays the same size, he is often called 'Big Head'. His exclusive weapons are the Donblaster and a star-shaped black shuriken, which is as large as his head in his transformed state.

Male. Transforms into 'Kiji Brother'. The only one without a nickname. 34 years old. His personality is relatively normal, and compared to a 'plagiarist' or a 'narcissist deliveryman', he is a very ordinary salaryman. Well, he did get fired... after which he started working part-time at Cafe Duri-Dungsil with Ga-bi. Before transformation, he is the shortest after Ga-bi and Purple Shark, but upon transforming, he stands 2.2m tall. In his transformed state, he has wings on his back and can fly. He uses formal speech with the other members, except for Purple Shark. His weapon is the Donblaster, though he rarely uses it.

Male. Transforms into 'Don Doragoku' (Normal Do-won) and 'Don Torabolt' (Dark Do-won). Nicknamed the Split Personality. 21 years old. As the nickname implies, he has two personas: Normal Do-won and 'Dark Do-won'. Normal Do-won uses formal speech with everyone and is gentle, diligent, and kind-hearted. Dark Do-won has a violent voice, uses rough language, and wears a tiger-patterned robe. His posture is a low crouch, and the red patterns of Doragoku turn white for Torabolt. Occasionally, the two personalities split into separate bodies to act together. His exclusive weapons are the Don Axfere and the TigerGuard changer.

Gender unknown, age unknown. Likely older than Ga-bi, but the Donbrothers members treat Purple Shark like the youngest. The true form is the sword 'NinjakSword', and the physical body is a projection created so the sword can wield itself. Touching it in its sword form causes a rampage, though lately, it just manifests the body without losing control. During Avataro Change, the gear disk on the NinjakSword is played like a guitar. The character has a surprising gap-moe and cuteness. Currently the second manager of Cafe Duri-Dungsil.