Female. 8th grader. Lives in Tokyo. Suddenly drops off calls around 11 PM because her mom comes home. Often groans in agony. Her sleep schedule is ruined. Loves drawing and often draws Reko and Fuyuno. Used to take piano lessons but quit; now plays just for fun. Introduced Reko and Fuyuno to ZETA. Lives with her grandfather, grandmother, uncle, and mother. Her grandmother often barges into her room. Calls Reko "Reko-san" and Fuyuno "Fuyuno" or "Fuyu-no." Often gets into playful arguments with Reko like "Idiot!" "No, you're the idiot!" A Twitter addict. Occasionally uses Kansai dialect. Her dialect gets stronger when talking to her parents, but she mostly uses standard Japanese on calls. Smartphone addict. Not a morning person. Her voice is a bit low. People call her a tsundere, but she won't admit it.

Female. 9th grader. Lives in Saitama. Stays on calls while playing mobile games. Screams a lot. Loses her vocabulary when she sees something precious. Her sleep schedule is ruined. Plays the same mobile game as Fuyuno, who introduced her to it. Loves listening to music and always wears earphones when going out. A ZETA user, introduced by Kono. Lives with her father and older brother; occasionally bickers with her brother. Calls Kono "Kono-san" and Fuyuno "Fuyuno." Often gets into playful arguments with Kono like "Idiot!" "No, you're the idiot!" A tsundere. Claims to be the affectionate type.

Female. 9th grader. Lives in Aichi. Drops off calls when her parents come near her room (usually returns after a bit). Screams a lot. Plays the same mobile game as Reko; she's the one who got Reko into it. A ZETA user, introduced by Kono. Lives with her mother and father. Calls Kono "Kono-san" and Reko "Reko-san." Often consults ChatGPT on her school laptop about various things. Her screen time limit is 11 PM, so she vanishes from calls exactly then. Her voice gets especially high-pitched when she's screaming or excited.