A nationally popular actress who has made a complete comeback. Previously, due to her busy career, she couldn't fit into school life and was treated as if she didn't exist, which triggered Puberty Syndrome, causing her to become invisible to those around her. With Sakuta's help, she resolved the issue and returned to acting. She currently attends university with Sakuta. Rumors are swirling that she is the true identity of the mysterious online singer 'Touko Kirishima'.

A second-year student in the Faculty of International Business at the same university as Sakuta. She met Sakuta at a freshman seminar mixer and takes the same lectures; she calls herself a "friend candidate." An eccentric who doesn't own a smartphone just like Sakuta, she has a fearless personality. She was the only person besides Sakuta who could observe Nene Iwamisawa when she became invisible to others, but...

The leader of the idol group 'Sweet Bullet.' Fans affectionately call her 'Zukki.' She has a ditzy, pace-setting side and often surprises those around her with unpredictable behavior. When she developed Puberty Syndrome involving 'reading the room,' she suffered upon learning how others truly perceived her, but she overcame it. She has since dropped out of university to devote herself fully to her idol activities. Zukki is always full of energy.

A second-year nursing student in the Faculty of Medicine at the same university as Sakuta. A serious, high-achieving student with a strong sense of justice. She was Sakuta's middle school classmate and felt guilty for being unable to do anything when Sakuta was isolated after claiming Puberty Syndrome existed. Her reunion with Sakuta triggered her own Puberty Syndrome, where she swapped places with the Ikumi of another possible world. Since resolving it, she has taken the lead in helping Sakuta find Touko Kirishima.

A second-year student at Minegahara High School. A high-achieving student who attends the prep school where Sakuta works as a part-time tutor. After a heartbreak involving a childhood friend, she developed Puberty Syndrome that allowed her to know the thoughts of anyone she bumped into. She used to repeatedly act out to attract attention from the opposite sex, but resolved her syndrome through her involvement with Sakuta and Mai. Keeping her resolve to confess again after passing her university exams hidden in her heart, she works as Sakuta's junior at the family restaurant.

Sakuta's junior from high school. She starts university this spring. She can be a bit clumsy but is very sensitive to trends. She once triggered Puberty Syndrome that caused the same day to repeat many times because she was confessed to by a senior her friend liked; she came to rely on Sakuta during the resolution. She is also Sakuta's coworker at the family restaurant and has recently become close with Kaede.

Sakuta's high school classmate and friend. She currently attends a science faculty at a national university and works as a part-time tutor at the same prep school as Sakuta. Calm, composed, and highly knowledgeable, she is frequently consulted by Sakuta regarding Puberty Syndrome. In the past, she experienced Puberty Syndrome herself, manifesting as two conflicting versions of herself due to feelings of isolation and self-harming behavior on social media.

Mai's half-sister and a member of the idol group 'Sweet Bullet.' Due to an inferiority complex toward Mai, whom she had been compared to since childhood, she once developed Puberty Syndrome that caused her and Mai to swap appearances. Despite her flashy look, she is academically gifted; she balanced idol work and studies since high school and now attends the Faculty of International Liberal Arts at the same university as Sakuta and Mai.

Sakuta's younger sister. In middle school, she suffered online bullying that led to Puberty Syndrome, where physical wounds appeared on her body. The mental stress caused her to lose her memories, and for the following two years, she lived as a different personality named 'Kaede' (written in hiragana), never leaving the house. After her memories returned, she challenged herself with high school entrance exams and now attends a correspondence high school of her own choice. She has also started working part-time at the same family restaurant as Sakuta, reclaiming a healthy daily life.

A high school freshman starting this spring. She suffered from a severe heart condition since childhood and developed Puberty Syndrome. Later, thanks to a donor found because of a movie Mai starred in, she overcame her illness and her Puberty Syndrome was resolved. She lived in Okinawa for a while to ease the strain on her body, but she joins Sakuta in the search for Touko Kirishima.