First person: I (soft, polite) Aki Miyashita / (After transformation) Agira Birthday: May 12 Blood type: O Age: 16 The listless atmosphere from the original work is faithfully reproduced, making her an older-sister figure with a somewhat ennui vibe. Her horns and dorsal fins aren't growing directly from her body like Gomora's, but appear to be parts of the hooded parka she wears.

First person: I (polite, feminine) Miku Ushimaru / (After transformation) Miclas Birthday: October 15 Blood type: B Age: 16 A super healthy child. She hasn't caught a cold since the day she was born. She's a so-called muscle-head whose body moves before she thinks. A rookie in the Kaiju Girl combat sport "Daikaiju Fight," she has a dignified expression with a bellicose air. She looks like a wild child with tanned skin, body paint all over, and revealing clothes. Her trademarks are her healthy sun-kissed skin, long black hair tied in a ponytail, and prominent canine teeth. She is especially close with Reika, Aki, Benio, and others.

First person: I (polite, feminine) Reika Shiragane / (After transformation) Windom Birthday: October 1 Blood type: A Age: 16 Serious about everything and possesses strong intellectual curiosity. She is actually a hardcore otaku and fujoshi, the type who devotedly supports her favorite characters. Her characteristic eyes are represented by goggle-like accessories and glasses, and her bellows-like legs are arranged into hot pants and boots. She is characterized by her glasses and long silver hair in braids, but the braids come undone when she transforms. She snipes enemies with a laser fired from the top of her head.

First person: I (polite, feminine) Pigmon Birthday: September 4 Blood type: O The instructor for GIRLS and an idol-like presence. She goes at her own pace with everyone and never stops smiling, but shows a strong core when it counts. A Kaiju Girl who inherits the soul of the mascot character Pigmon. The content of her Kaiju Soul is a love for humanity—"I really love people." Her design is quite cute, with things like Pigmon scales on her arms and legs, and her chest covered by cloth.

Zetton Birthday: Unknown Blood type: Unknown The absolute champion of "Daikaiju Fight" and the strongest Kaiju Girl in GIRLS. She is a celebrity known to everyone in the world, yet she is a girl of many mysteries who boasts overwhelming silence and an ironclad lack of expression. Other Kaiju Girls don't seem to know where she is or what she's doing normally; she is more famous than anyone, yet more shrouded in mystery than anyone. She seems to care for the other Kaiju Girls as comrades, casually throwing words of encouragement or supporting Agira's actions from the shadows.

Benio Utagawa / Red King Birthday: September 4 Blood type: O A talented competitor in "Daikaiju Fight." She has many fans for her "might is power" battle style. Her real name is Benio Utagawa. First person: I (rough, masculine). The first champion of Daikaiju Fight. She has currently yielded that position to Zetton and engages in fierce battles to avenge her loss, but falls just short. During combat, her personality becomes a mass of fighting spirit, and her forte is powerful combat utilizing her superhuman strength. In battles against Gomora and Zandrias, she has demonstrated moves like the giant swing. In truth, she is an extreme girly-girl who loves cute things beyond measure.

Eleking Birthday: November 15 Blood type: AB A cool beauty with cold eyes, she is one of the senior Kaiju Girls to Agira and the others. A solitary fujoshi who never flocks with others. Her transformed appearance is a bikini-like outfit modeled after Eleking, and she attacks with a whip and shield resembling Eleking's tail. She is a lone wolf who gives a somewhat unapproachable impression with a blunt personality and sharp tongue, but according to Pigmon, she is "very kind at heart." Her transformed state is inspired by a female knight.

Mikazuki Kuroda / Gomora Birthday: January 8 Blood type: B A promising up-and-comer in Daikaiju Fight. Her special move is the "Megaton Tail," where she rotates her body vertically and uses that momentum to slam her tail down on the opponent. On the other hand, she has a habit of speaking her mind clearly, for better or worse. Her appearance can be summed up as a "school-swimsuit little girl."

Sachiko Dori / Zandrias Birthday: April 23 Blood type: A She was a stray Kaiju Girl but was taken in by Red King and is currently active as a GIRLS apprentice. Her rebellious phase seems to be finally settling down? Her design is a cute, devil-girl style rearrangement, with two horns on her head, wings on her back, and a swimsuit-like outfit that retains traces of a shell. The detail is quite fine, such as the loose skin on her legs being arranged like loose socks. Also, she wears a sailor uniform on her upper body and, for some reason, a school swimsuit underneath it.

Clara Sorne / King Joe Birthday: January 7 Blood type: B A science girl born in America. She is a beauty that everyone would turn to look at if she stayed quiet, but she has a bottomlessly bright and cheerful personality, being broad-minded and not sweating the small stuff. She is quite beautiful and also active as a model, but her personality is very bright contrary to her looks. She can attack enemies by separating parts of her waist and controlling them remotely. Besides firearms, the parts can also fire white wire-like objects to bind the opponent's movements.