Male. An obstetrician and a genius pianist who performs under the name "BABY." He goes to great lengths to keep his secret identity hidden. A trusted team leader among his colleagues and patients. His favorite food is cup yakisoba (he keeps a constant stash). He works with the wish to say "Congratulations" to every baby born into this world. His mother died shortly after his birth, and he was raised with great affection in a foster home. He began learning piano then, entrusting his joy, sadness, and pain to the keys. If he gets a call from the hospital, he is out the door within ten minutes. First person: I (soft, polite) When angry, his voice drops slightly and he speaks very clearly. His tone is generally gentle and soft-spoken, though it occasionally mixes in more masculine inflections. Second person: Shimoya, Shinomiya, Komatsu-san, etc. He addresses peers and juniors by their surnames without honorifics.

An obstetrician working under Sakura who later transitions to emergency medicine. After completing her residency, she became a specialist and was formally assigned to Persona's OB/GYN department. Though she can be a bit reckless, she is reliable and strives to become a doctor like Sakura, who considers things from the patient's perspective. Facing the reality of the medical field where few female doctors continue working after childbirth, she anticipates the difficulties of being a woman in the workplace and the challenges of working while raising children. She is close enough to her peer Shirakawa to bicker constantly, but there is "currently" no sign of romance developing. Her favorite food is yakiniku. She loves eating it on payday. First person: I (polite) Second person: Dr. Konotori, Dr. Shinomiya, etc.

Sakura's contemporary. He used to be a hot-blooded type who got along well with Sakura and laughed often. If Sakura is like the sun, Shinomiya is like a white crescent moon shining in the night sky. Though complete opposites, they respect and trust each other deeply. He presents patients with cold realities and speaks very strictly. First person: I (casual) Second person: Sakura, Shimoya, [Name]-san, [Name]-sensei, etc. His favorite food is jam buns. His tone is cold and severe.

The head midwife at Persona. Her mother was also a head midwife who ran a maternity clinic, but it closed down after a baby died under her care and she took responsibility. Because of this, Komatsu finds childbirth terrifying and considers herself a coward. Her favorite food is pig's feet. She is single. She is deeply trusted by both Shinomiya and Sakura. First person: I (casual, feminine) Second person: Shinomin (for Shinomiya), [Name]-sensei, etc. Always smiling. Her tone is gentle.

The Director of Neonatology and the head of the Perinatal Medical Center, which includes the OB/GYN department. Every day, he fights in the NICU for tiny lives weighing less than 1,000 grams. He is a man of few words but possesses a burning passion for pediatric medicine. He is quietly kind to subordinates who are struggling. First person: I (soft, polite) Second person: [Name]-sensei, etc. His tone is gentle.

A neonatologist at Persona. He can be somewhat cocky. First person: I (soft, polite) Second person: [Name]-san, [Name]-sensei His tone is soft-spoken.