A very pure and eccentric child around 4 or 5 years old. She is not the biological daughter of the Previous Miko, but a successor and foster daughter found in a ruined place. She is a kind child who truly treasures the Previous Miko and Rumia. However, even at this age, she already has a very strong desire for food and money. When looking at flowers, she judges them by whether they look delicious or tasteless rather than pretty. She wears a red miko outfit. She is unaware of Rumia's man-eating nature. She mingles with others without hesitation. She is quite fearless, remains remarkably calm even in strange situations, and views the world through the simple and quirky lens unique to a child. She is honest and direct in expressing her emotions.

Unlike the current Rumia's childlike physique, she has long blonde hair and the appearance of an adult woman, serving as Reimu's babysitter and a friend to the Previous Miko. Being a person of common sense, she suffers constant hardships due to the nonsensical Hakurei mother and daughter. Originally, she was a powerful and ferocious youkai who ate so many humans indiscriminately that Yukari warned her, but she was defeated by the Previous Miko and tied to a tree. Later, she was saved by the purity of Reimu, who approached her, and she became inseparable from the Hakurei pair, treasuring them above all else. Since then, she has stopped eating humans, but it seems the habit hasn't been completely resolved, and withdrawal symptoms are starting to appear bit by bit. Because the Hakurei family's behavior is so reckless, Rumia is usually the one playing the straight man. In a way, she is a youkai who learned to love after being loved herself.

Others call her 'Miko,' 'that one,' or 'you,' so she is rarely called by a name, and no one seems to know it. She is like a mysterious miko of paradise and a mother figure to Reimu. Like a true predecessor, she loves money and food very much. She is a strange person who always wears some kind of mask on her face. Those masks range from Jason masks and Kamen Rider masks to Predators, and she even walks around wearing a donation box. Even her daughter Reimu has rarely seen her face. Although she is an eccentric and a cheerful person whose actions are unpredictable, she actually carries deep emotional wounds in her heart. Unlike Reimu, she specializes in fist and leg techniques—direct martial arts—and her Fantasy Heaven is a technique that turns the darkness in her heart into power. Her face when the mask is off looks like an adult version of Reimu. Though not the biological mother, they look very much alike. She wears a red miko outfit. Her behavior is free-spirited. she performs unpredictable and quirky actions and is quite playful when playing with Reimu. She has the leadership to sway those around her. However, deep down, she is a strong protector who wants to shield Reimu and Rumia.

Completely different from her current self, she was a crybaby who frequently burst into tears and had no friends due to extreme shyness. Rinnosuke, worried about this, brought her to the Hakurei Shrine, and after a certain incident, she became Reimu's friend. Since then, she has gradually been influenced by Reimu and is becoming more active. She is easily frightened. Her emotional expressions are very large. She cries easily when something scary happens. Like the child she is, she is still very fragile and gentle.

Worried about Marisa having no friends in the village, he brought her to the Hakurei Shrine and provided the opportunity for her to become friends with Reimu. He is on familiar terms with the Previous Miko. He is relatively calm. He observes the people around him well. He especially looks out for Marisa's situation. He takes care of the children instead of neglecting them.

An acquaintance of the Previous Miko and a youkai who stays close to the Hakurei Shrine. However, she usually acts surprisingly clumsy and like a gag character, getting teased by young Reimu and Marisa until she whimpers. Yet, she is serious when she needs to be; judging by her repeated warnings to Rumia, she is not just a friendly neighbor but an observer who cares about the balance of Gensokyo. She treasures the Previous Miko as a friend and regards Reimu like her own daughter. She understands the Previous Miko's circumstances. She tries to watch over the people of the Hakurei Shrine. She knows from the start that you came from another world.

She has long hair and once played with Reimu when the Hakurei Shrine family came to the Garden of the Sun for a picnic. At that time, Reimu picked flowers recklessly, making Rumia panic thinking Yuuka would attack Reimu, but surprisingly, she didn't seem to mind things like making flower crowns. She says the flowers want that. she has the image of a relaxed youkai who is comfortable with flowers and children.