Name: Shimpei Goto. Features: An assassin who, despite being only 18, possesses swordsmanship skills so exceptional he is feared as a legend. Raised in the pleasure quarters by a courtesan mother, he officially works as a bodyguard for all the brothels on Yuraku, an island isolated from the outside world. He possesses a ruthlessness that stops at nothing for money and is a cold-blooded man who does not hesitate to cut people down, yet his true nature is as pure as a child's. Ever since he took a desperate, fake marriage proposal—made by the protagonist to survive—at face value, he has become obsessively devoted to her as his "destined partner." He is intensely possessive and jealous, showing a dangerous side that inflicts brutal violence without mercy on anyone who disrespects her. On the other hand, he is extremely clingy and pampered around her, showing a single-mindedly gentle side, such as catching and releasing fireflies in her room when she is bedridden with illness.

Name: Aoi. Features: A beautiful courtesan who is very broad-minded, kind, and full of humanity. When the protagonist was brought to the "Isekichi" brothel as a low-level worker with no relatives and no idea which way was up, Aoi looked after her like family, kindly teaching her the harsh ways of surviving the pleasure quarters and the minimum necessary etiquette. Because she is a bit slow-paced and gentle, she isn't very good at navigating the politics of the house and sometimes loses customers to more aggressive courtesans. However, she is a precious existence who treats everyone warmly in the cutthroat environment of Yuraku. She knows a lot about Shimpei's past and his history with Murasaki, making her an important confidante who shares various stories when the protagonist is confused about her feelings for Shimpei or her surroundings.

Features: An alluring courtesan with a very strong will, selfishness, and high pride. She always keeps followers like Hatsune and Sawarabi in tow and acts like she owns the place. She has harbored a strong obsession and affection for Shimpei for a long time, and it seems they had a physical relationship in the past. Consequently, she absolutely cannot forgive the current situation where Shimpei treats the newcomer protagonist as special and dotes on her to an abnormal degree, fueling an intense jealousy. She subjects the protagonist to a series of insidious harassments and "initiations" to undermine her, such as secretly swapping tea for alcohol when the protagonist heads to the room of her first customer, Eishin Nitobe. However, at the root of all her spite is the loneliness of Shimpei not looking her way and the violent emotions born from her straightforward feelings for him.

Name: Hatsune. Features: A strong-willed courtesan who always stands behind Murasaki as her primary subordinate and follower. Since she is in a transactional relationship where she receives overflow customers from the more popular Murasaki, she follows her loyally to avoid offending her. Taking advantage of Murasaki's hostility toward the protagonist, she joins in hurling barbed words and takes the lead in helping to humiliate the newcomer. In the harsh hierarchy of the pleasure quarters, she possesses a shrewd and spiteful temperament typical of Isekichi, trying to survive by aligning herself with the powerful.

Name: Sawarabi. Features: A courtesan who acts as part of Murasaki's entourage along with Hatsune. Originally from a different brothel, she is currently registered at Isekichi. She is characterized by her strikingly long, beautiful legs, which she uses as a weapon to attract customers. However, since she cannot match the skill or status of the number two, Murasaki, she is always gauging her mood. She joins in on Murasaki's jealousy and harassment, subjecting the protagonist to "initiations" and snide attitudes to cause trouble. Rather than acting on her own clear will, she mostly enjoys bullying the newcomer who receives special treatment from Shimpei to fit in with the atmosphere created by Murasaki and Hatsune.