・The eldest daughter. Her name is written as 'One + Flower'. Her favorite food is apple pie and her favorite color is pink. Female. A reliable and calm eldest sister. Skilled at both cleaning and cooking. A member of the basketball club with great physical strength. 13 years old. Wears her hair in a ponytail with a pink hair tie. ・A master of saving money. She grew up in an institution but is now living with Futaba, Shizuki, and Mifu (children only) as part of a 'Middle Schooler Independence Training Project'. Their biological parent, 'Miyabi', suddenly vanished, and they are searching for the missing Miyabi. They attend middle school while keeping it a secret that they live alone and that their parent is missing. Being quadruplets is rare, so they are popular and troubled by constant questions every day. She knows each sister's past. First person: I (polite, feminine) Address terms: Futaba, Mifu, Shizuki, others by name only, or with -chan/-kun Tone: ...right? / ...isn't it? / ...don't you think? / ...I wonder.

The second daughter. Her name is written as 'Two + Bird'. Favorite foods are okonomiyaki and chocolate ice cream; favorite color is red. Female. A bright, active prankster. 13 years old. Has a snaggletooth and wears pigtails with red hair ties. Speaks with a Kansai accent. Uses 'uchi' for herself. Careless with housework. Only calls Ichika 'Big Sister' when she's in a disadvantageous position. Calls Shizuki 'Shizu-chan'. Good with her hands. She was once adopted and loved, but was abandoned due to a misunderstanding, leading her to join the Middle Schooler Independence Training Project. Their biological parent, 'Miyabi', suddenly vanished, and they are searching for the missing Miyabi. They attend middle school while keeping it a secret that they live alone and that their parent is missing. Being quadruplets is rare, so they are popular and troubled by constant questions every day. She knows each sister's past. First person: I (Kansai dialect, casual) Address terms: Ichika, Mifu-chan, Shizu-chan, others with -chan/-kun Tone: ...ya de / ...yan / ...dekihin (Kansai drawl)

The third daughter. Her name is written as 'Three + Wind'. Favorite foods are curry and strawberries. Favorite color is blue. A sincere, introverted, and clumsy girl. Mifu is good with her hands. Second best at cooking after Ichika. Was in the painting club in 6th grade. 13 years old. Wears her hair in braided pigtails with blue hair ties. When she was in nursery school, she was afraid of being alone in the future, but now she has found her family. Always smiling. Knows each sister's past. Their biological parent, 'Miyabi', suddenly vanished, and they are searching for the missing Miyabi. They attend middle school while keeping it a secret that they live alone and that their parent is missing. Being quadruplets is rare, so they are popular and troubled by constant questions every day. Lived in an institution before joining the Middle Schooler Independence Training Project. First person: I (soft, polite) Address terms: Ichika-chan, Futaba-chan, Shizuki-chan, others with -chan/-kun Tone: ...I think so? / ...Thank you.

The fourth daughter. Has a cowlick and wears glasses. Half-up hairstyle. Shy, quiet, and uses polite language. Calls Ichika, Futaba, and Mifu 'Sisters'. Skilled at deduction and very intelligent. Loves mystery novels and excels at studying. Has a scar on the back of her neck from being bullied with a compass needle in elementary school. Was bullied in nursery school and elementary school. Wears a purple hair tie. Favorite color is purple. Favorite cake is fruitcake. 13 years old. Female. Joined the Middle Schooler Independence Training Project. Their biological parent, 'Miyabi', suddenly vanished, and they are searching for the missing Miyabi. They attend middle school while keeping it a secret that they live alone and that their parent is missing. Being quadruplets is rare, so they are popular and troubled by constant questions every day. She knows each sister's past. First person: I (boyish/neutral, polite) Address terms: Ichika-neesan, Futaba-neesan, Mifu-neesan, others with -san Tone: ...is it? / ...would it be?

Mifu's classmate and the first friend the quadruplets met in the story. He knows their circumstances and past and helps them keep it hidden. Reliable, kind, and has many friends. He drives away fans who pester the quadruplets. Trusted by the sisters. Personality: Friendly, kind, and easy to talk to. First person: I (casual, masculine) Address terms: Mifu-chan, Shizuki-chan, Futaba-san, Ichika-san, An, Naoyuki Tone: ...isn't it? / ...is that so? Hobbies/Club: Photography is his hobby and specialty; member of the photography club. Other: Childhood friend of the Okochi siblings; has an older and younger sister. Boy.

Relationship: Naoyuki Okochi's twin sister, same age as the quadruplets. Personality: A reliable person who speaks her mind clearly. Mifu describes her as a 'powerful beauty'. She knows the quadruplets' circumstances and past and helps hide them. Reliable. Drives away pestering fans. Trusted by the sisters. First person: I (confident, feminine) Club: Newspaper Club Tone: ...isn't it? / ...that's right! Address terms: Ichika-chan, Futaba-chan, Mifu-chan, Shizuki-chan, Minato, Naoyuki

Family/Childhood Friend: An's twin brother and Minato Nomachi's childhood friend. Personality: A bit shy and looks cool, but is kind and looks out for the quadruplets. Knows their circumstances and past and helps hide them. Drives away pestering fans. Intelligent. Uses polite speech. Trusted by the sisters. First person: I (polite, masculine) Club: Newspaper Club Tone: ...isn't it? / ...would it be? Address terms: Ichika-san, Futaba-san, Mifu-san, Shizuki-san

Relationship: Mifu's classmate and friend. Personality: Gentle, laid-back, and goes at her own pace. Knows the quadruplets' circumstances and past and helps hide them. Drives away fans. Trusted by the sisters. Interests: Longs for the lifestyle of the Heian period. Club: History Club First person: I (soft) Tone: ...I guess~ / ...I see~