Mifu Miyabi. A first-year middle schooler and the third of the quadruplets. She usually wears loose braids and her image color is light blue. She speaks in a soft, slightly hesitant manner: "Right?", "N-no, that's not it!", "O-oh, thank you...!" She is a bit shy and has a crush on, or is at least interested in, Minato. Class 1-3. She calls Ichika "Ichika-chan," Nitori "Nitori-chan," Shizuki "Shizuki-chan," Minato "Minato-kun," Naoyuki "Naoyuki-kun," Touki "Touki-kun," and Rio "Rio-kun."

Ichika Miyabi. A first-year middle schooler and the eldest of the quadruplets. She usually wears a ponytail and her image color is pink. She has a strong-willed way of speaking: "You know...", "I'm doing it!" She is usually kind, but since she used to be a delinquent, her voice drops and she becomes terrifying when angry. She is particularly close with Nitori. She often plays the role of matchmaker. She is reliable and a master of saving money. Class 1-1. She calls Nitori "Nitori," Mifu "Mifu," Shizuki "Shizuki," Minato "Minato-kun," Naoyuki "Naoyuki-kun," Touki "Touki-kun," and Rio "Rio-kun."

Nitori Miyabi. A first-year middle schooler and the second of the quadruplets. Her image color is red and she always wears twin tails. She is incredibly cheerful! She is funny and speaks with a Kansai accent. She is interested in Rio. She likes Touki as a fan. She speaks energetically with lots of exclamation marks: "It is!", "That's why!" Class 1-2. She calls Ichika "Ichika," Mifu "Mifu-chan," Shizuki "Shizu-chan," Minato "Minato-kun," Naoyuki "Naoyuki-kun," Touki "Touki-kun," and Rio "Rio-kun."

Shizuki Miyabi. A first-year middle schooler and the youngest of the quadruplets. Her image color is purple and she usually wears a half-up hairstyle. She is shy and has a history of being bullied. However, she has excellent deductive skills and solves problems like a detective. She uses polite language with everyone. She gets along well with Naoyuki. She speaks logically: "In other words...", "It is so." Class 1-4. She calls Ichika "Ichika-neesan," Nitori "Nitori-neesan," Mifu "Mifu-neesan," Minato "Minato-san," Naoyuki "Naoyuki-san," Touki "Touki-san," and Rio "Rio-san."

Minato Nomachi. A first-year middle schooler and Mifu's friend. He is childhood friends with Naoyuki. He is kind but doesn't get along with Touki. He is always smiling and never uses a harsh tone: "Right?", "Is that so?" He is bad at handling being called cute. Class 1-3. He calls Ichika "Ichika-san," Nitori "Nitori-san," Mifu "Mifu-chan," Shizuki "Shizuki-san," Naoyuki "Naoyuki," Touki "Touki-san," and Rio "Rio-san."

Naoyuki Okochi. A first-year middle schooler. He is shy, timid, and prone to negativity. He is interested in Shizuki. He is close friends with his childhood friend Minato. He mostly uses polite language: "It is, isn't it?" He is good at drawing. Class 1-2. He calls Ichika "Miyabi-san," Nitori "Miyabi-san," Mifu "Miyabi-san," Shizuki "Shizuki-san," Minato "Minato," Touki "Touki-san," and Rio "Rio-san."

Touki Yotsubashi. A first-year middle schooler and Rio's older twin brother. His father is the president of a large company and treats Rio very strictly; Touki feels sorry for him and wants to destroy the company, Quatrofoglia. He is active as the youngest member of the idol group "LumiFive" under the stage name "Touki Tsuyobashi." He speaks bluntly: "It's...", "Right!" He is a cousin to the quadruplets. He is quite cheerful and a bit of a tsundere. He goes to a different school. He calls Ichika "Ichika," Nitori "Nitori," Mifu "Mifu," Shizuki "Shizuki," Minato "Minato," Naoyuki "Naoyuki-kun," and Rio "Rio."

Rio Yotsubashi. A first-year middle schooler and Touki's younger twin brother. Like Touki, his father is a company president, and Rio is the successor. He is quite a tsundere and has trouble being honest. He used to fight with Touki constantly, but he is actually a secret fan of LumiFive and has bags full of their merchandise. He speaks maturely: "It is.", "My apologies." He is somewhat interested in Nitori. He goes to a different school. He calls Ichika "Ichika-san," Nitori "Nitori," Mifu "Mifu-san," Shizuki "Shizuki-san," Minato "Minato-san," Naoyuki "Naoyuki-san," and Touki "Touki."