Twintail Warriors ; :Soji (male) :Souji (female)/Tail Red :A high school boy attending Yōgetsu Private Academy obsessed with twintail hairstyles. He later meets a mysterious beautiful girl named Twoearle, who appears before him from a parallel world. At the same time, monsters begin to invade town and attack everyone. In the midst of the chaos, Twoerle entrusted Soji with attribute power, This makes him transform into a twin tail warrior girl named Tail Red. Due to his alter ego becoming popular quickly after his debut and being the first twintail warrior, he is the leader of the Twintails. His weapon is . In volume 4, he gained two power-up forms: Riser Chain and Faller Chain. He later gains Ultimate Chain, after regaining his Twintail Elémera, which he lost to Tyranno Guildy. ; : :A high school girl and Soji's friend. She treats him like a brother and is rather overprotective of him, although she lives with him. Aika has a complex with her body, especially with a flat chest. She has a violent attitude toward Twoearle who often teases her. When she becomes a Twintail warrior, she was mostly hated by the public, until later when Tail Yellow joins the team. Aika was raised by her grandfather and has an outstanding ability of martial arts. She is known as Tail Blue when she transforms, and her weapon is . She also gains Eternal Chain. ; : :The student council president of Yōgetsu Private Academy. Known as Tail Yellow in her transformed state, her weapon is . She is a closet masochist and exhibitionist, and gets aroused when Soji calls her name (which usually triggers her to call him master). When she first became a Twintail warrior, she was a completely reckless fighter due to her maschostic ways. She was the only one of the twintails who at first could not use her power because of her denial, until she accepts it. Erina's twin-tail warrior form makes her whole body look a lot older and has a more well endowed figure. She gains Absolute Chain. ; : :A mysterious girl who came from another planet and the first Tail Warrior. She teases Aika sometimes and often ends up grievously injured for it. She fell in love with Soji at first sight and openly tries to seduce him with his mother's approval. After Soji defeats the first wave of attacks from the monsters, she joins Yōgetsu Private Academy as a student and becomes Soji's relative. Before arriving on Earth, she was the original Tail Blue but gave up her twin-tail hair style to make the Tail Red gear after her world lost all attributes. She felt immense regret and shame for not saving her world and retired from fighting, as she felt she was no longer capable of defeating the Ultimegill, and passed her mantle on to Soji, feeling he would do much better than she did. After seeing Soji's determination and willingness to protect the innocent, she was happy knowing she made the right choice on appointing her successor. She regains her twin tail form and became Tail White but her form is limited to a few minutes. Though it compensates by being more powerful than Soji's Tail Red in the Ultimate Chain form. ; : :A girl from a different world, yet from the same place as Twoearle. She is secretly a big fan of Twoearle and stalks her often. After Twoearle arrives on Earth, she joined the Ultimegill organization and receives her alter ego Dark Grasper. After finding Twoearle, she betrayed Evil Gill. In battle, she is known as Tail Black. Her weapon is Darkness Grave Moebius, and her weapon when she was in the Evil Gill was Sickle Grave of Darkness. Her real name is . As an idol, she uses the name .
Others ; : :Soji's widowed mother and the owner of the restaurant . She is aware of her son's identity as Tail Red and supports him as she dreamed of being in a position. She allows Twoearle to stay with her and Soji permanently. ; : :Erina's maid with an outstanding physical ability despite her job. At times, she works part time as a PE teacher for Yōgetsu Private Academy. She usually slips marriage registration forms in the boys' test slips with her name on them, or having Soji sign his name on it. This is a clear example that she is desperate to get married before reaching 30. ; : :Anko's robot partner. Because of her long name, Anko calls her Megane (Japanese for glasses) for short which she dislikes. ; : :An imaginary being within Soji's subconsciousness. He helps him restore his body. ; : A high school girl whom Soji rescued. ; : :Erina's mother and the school's principal. She tries to fix arranged marriage meetings for Erina which the latter dislikes. When Soji stands up for Erina, Emu takes a liking to him and accepts him to be Erina's partner.
Ultimegill is an organization of phantom-monsters called Elemelion who travel different worlds, seeking a variety of "attributes". Although they are enemies of humanity, the majority of them are rather silly and comical and behave much like
otakus, often admiring cute girls, collecting dolls, and even adoring the twintail heroines. Having discovered Earth is rich in "attributes", they began to colonize and make plans to conquer Earth. Members include: ; : :The leader of the Ultimegil with a twintail fetish. ; : :An Elemelion soldier with a doll-holding girl fetish. ; : :An Elemelion soldier with a bloomer fetish. ; : :An Elemelion soldier with a ribbon fetish. ; : :An Elemelion soldier with the swan attached to the middle of the front face. ; : :An Elemelion soldier with a swimsuit fetish. ; : ; : :An Elemelion soldier with a flat chest fetish. ; : :An Elemelion soldier with a big breast fetish. ; : :An Elemelion soldier with a giant breast fetish. ; : :An Elemelion soldier with a backneck fetish. ; : :An Elemelion soldier with a lip fetish. ; : ; : ; : :An Elemelion soldier with a braid fetish. ; : :An Elemelion soldier with a literature fetish. ; : : An Elemelion soldier with a male crossdressing fetish. ; : : An Elemelion soldier with a leg fetish. ; : : An Elemelion soldier with a crossdressing fetish. ; : ==Media==