Shirayuki is a pharmacist living on the country of Tanburn who is chosen by the prince to become his concubune due to her rare beauty, but she decides to flee instead. On her escape, she meets and befriends Zen, who happens to be a prince from the kingdom of Clarines and offers her shelter.

Starting her new life on Clarines, Shirayuki sets on a quest to find some herbs, and worried about her safety, Zen decides to look after her, just when she finds herself in dire straits again.

Due to her closeness with Zen, Shirayuki is now a regular visitor to his castle with no restrictions. However, there are those who doubt her intentions and conspire to separate her from the prince.

Shirayuki takes the court pharmacist exam where her knowledge of plants are tested. Once passing the test, she is assigned to be an apprentice under Ryuu, another young prodigy like her, who soon becomes her friend.

When the soldiers from Fort Laxdo fall sick to a strange disease, it's up to Shirayuki to discover the mystery behind it and find a cure.

Izana, the crown prince of Clarines and Zen's elder brother returns home and wary of Zen's relationship with Shirayuki, invites Raji for a visit to Clarines with unknown intentions.

As Raji continues his tour, Izana confronts Zen and Shirayuki about the true nature of their relationship, and in the occasion, the bond between the two grows stronger.

Alert with the unwanted attention Shirayuki receives due to her closeness with him, Zen sends his aide Obi to be her personal guard. Meanwhile, Mitsuhide, another of Zen's loyal subjects, reminisces the occasion when he first met his master.

While standing as Shirayuki's protector, Obi learns more about her, while Zen finally recognizes his merit and makes him an official retainer of his.

Shirayuki meets Kiharu, a young girl who comes to the castle with her pet bird Popo to ask Zen to help protect the birds of Popo's species of her home island who are threatened by local poaching. However, there is nothing Zen can do for Kiharu's cause unless the birds can prove themselves useful for Clarines' society, until Shirayuki comes with an idea.

After being kissed by Zen, Shirayuki becomes too flustered to face him directly, while Zen, despite eager for an answer from her, must leave for a short trip with Mitsuhide and Kiki. Once reunited, Zen and Shirayuki finally share their true feelings for each other.

The castle is open for a festival and Zen disguises himself as a guard to enjoy it with Shirayuki and the others. However, an actress is forced to quit a play due to an injury and Shirayuki is chosen to replace her, unaware of the troupe leader's second intentions.