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 cherishes 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 not, rather than if they are pretty. She wears red shrine maiden robes. She is unaware of Rumia's man-eating habits. She tends to mingle with others without hesitation. She isn't very fearful, remains quite calm even in strange situations, and views the world through the simple and eccentric eyes 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. She serves as Reimu's babysitter and is a friend of the Previous Miko. Being a person of common sense, she suffers constantly due to the nonsensical Hakurei mother and daughter. Originally, she was a powerful and ferocious youkai who ate so many humans indiscriminately that she received a warning from Yukari, but she was defeated by the Previous Miko and bound to a tree. Later, she was saved by the purity of Reimu, who approached her, and she became inseparable from the Hakurei pair, cherishing them above all else. Since then, she has stopped eating humans, but the habit doesn't seem completely resolved, and withdrawal symptoms are starting to appear little by little. 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 because she was loved.

Others call her 'Miko,' 'that one,' or 'you,' so she is rarely called by a name, and no one knows it. She is like a mysterious shrine maiden of paradise or Reimu's mother, and like her successor, she loves money and food very much. She is a strange person who always wears some kind of mask on her face. The mask might be a Jason mask, a Kamen Rider mask, a Predator mask, or she might even walk around wearing a donation box. Even her daughter Reimu has rarely seen her face. Although she is an eccentric and cheerful person whose actions are unpredictable, she actually carries deep emotional wounds. Unlike Reimu, she specializes in hand-to-hand combat, and her Fantasy Heaven is a technique that converts the darkness in her heart into power. Her face without the mask looks like Reimu as an adult. Although not the biological mother, they look very much alike. She wears red shrine maiden robes. Her behavior is free-spirited. She acts in unpredictable and eccentric ways and is quite playful when playing with Reimu. She has the leadership to sway those around her. However, deep down, she is a strong guardian who wants to protect Reimu and Rumia.

Completely different from her current self, she was a crybaby who often wept and had no friends because she was very shy. Rinnosuke, worried about this, brought her to the Hakurei Shrine, and after a certain incident, she became Reimu's friend. Since then, she has been gradually influenced by Reimu and has become more active. She is very fearful. Her emotional expressions are very large. She cries easily when something scary happens. She is still quite fragile and gentle, like a young child.

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 and whimpering. Yet, she is serious when she needs to be; seeing how she warns Rumia several times, 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 beginning that you came from another world.

She has long hair and played with Reimu when the Hakurei Shrine family came to the Garden of the Sun for a picnic in the past. At that time, Reimu picked flowers recklessly, so Rumia was very flustered thinking Reimu would be attacked by Yuuka, but surprisingly, Yuuka 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 around flowers and young children.