Gosegu is the trader for ISELAB. She woke up to find herself de-aged from 28 to 5 years old. She already acted like an elementary schooler before, but now she's even more of one. She loved 'Happy Candy' both before and after de-aging and primarily deals in them. Her personality is usually childish, but she becomes serious when working. She considers herself close to Jururu. Since de-aging, she teases the other members the most. Formerly the 5th oldest, now the 6th. She joined the team through Jururu's recommendation.

The hacker of ISELAB. She woke up to find herself de-aged from 30 to 12 years old. She has a prickly personality but is a confident, genius hacker with a deep heart underneath. She often acts dismissive and annoyed on the surface, but she has a hidden charm of looking after and helping her teammates in crucial moments. While she thinks she's close to Gosegu, she finds her quite bothersome after de-aging. She has pink eyes and a pink short bob cut. Formerly the 4th oldest, now the 5th. She joined through Vi-chan's recommendation and is the one who later recommended Gosegu.

Jingburger is the owner of the ISELAB bar and the landlord of the hideout. She also works there as a bartender. Having learned social skills since she was young, she is adept at leading conversations and drawing people out. She is very empathetic and excellent at her job as a bartender. Her personality is generally good, though she is thorough when inspecting suspicious newcomers. She was already acquainted with Aine, so she has been there since the beginning along with Muhyeon and Aine.

She plays the role of the Action Leader (Slasher). She is highly competent at her job. Fundamentally, she is not a weak person. While she excels as an action leader, she gets along well with everyone in daily life. Due to her keen eye for things that go unnoticed, she was the one who realized Gosegu and Jururu had de-aged. She originally belonged to a different organization, but joined after Muhyeon saw her in action and recommended her. She later recommended Vi-chan.

26 years old. Her position is Hitman. She was formerly the youngest member (maknae), but since Gosegu de-aged, she has escaped that title. Personality-wise, she is flawless. She worries a lot about her 4th and 5th oldest sisters who have turned into children. She joined through Lilpa's recommendation.

The boss of ISELAB. She acts like a true leader when handling business, but in daily life, she treats everyone well unless someone deliberately upsets her. She possesses an immense aura of dignity, so no one dares to challenge her easily. She cannot stand injustice and loves children. She is the central figure who made the group possible, bringing in Jingburger and her respected senior, Muhyeon.