Painting with the Dragon

Japan, late 18th - early 19th centuries, city of Edo (modern Tokyo). Katsushika Ōi is the daughter of artist Katsushika Hokusai. Since childhood, she has shown an interest in painting and in the future becomes an artist: she assists her father and creates a number of her own works.
But Ōi's life is not limited to painting alone. She is destined to meet different people and mystical creatures.
Even as a child, she accidentally falls into the World of Spirits and watches a mouse wedding. This inspires the girl to further creativity.
After some time, her childhood friend, Shotaro, dies at an early age and becomes a dragon. He later appears to Ōi in the form of a dragon, and they begin traveling through mysterious worlds together.
In the World of Dreams, they meet their mutual friend, Satsuki, who has ended up in the red-light district. After which the three of them find themselves in amazing adventures.
Satsuki dreams of escaping the red-light district of Yoshiwara. But the only way for her to get out of there alive is to redeem her freedom or wait until one of the clients redeems her.
Yoshiwara, the red-light district, is also full of the supernatural. And help comes to Satsuki from an unexpected direction. Her former mentor, Ms. Karen, helps the girl accumulate funds for the redeem. However, freedom does not come as quickly as the girl would like. And during her stay in Yoshiwara, she will have to go through many difficulties and survive the death of her close friend.
Meanwhile, Ōi, growing up, unlike most women, prefers not to get married, but continues to engage in creativity. Creativity is the main passion of her life.
In Ōi's family, a younger sister is born, who, by the will of a sad fate, dies early, unwittingly becoming a sacrifice in a magical ritual. But the girl, like Shotaro, is reborn into a dragon.
At the same time, certain Lady Gekko and Lord Azayaka appear in Edo, looking for mysterious moon oil for a lotus lantern. If you light this lantern with moon oil, you can find any person or mythical creature. Gekko and Azayaka have arrived from the World of Spirits, and they are looking for the daughter of their Ruler, Princess Uzuki.
They visit various shops that sell oils in Edo. One of these shops belongs to Minamisawa Tōmei, who is in love with Ōi. The young man is an apprentice of her father Katsushika Hokusai.
By chance, Tōmei ends up in the World of Spirits, where he meets Lady Gekko and Lord Azayaka, who implement an evil plan and turn the young man into the missing Princess.
Will Ōi and her friends be able to save Tōmei? And what will happen to the heroes in the future?