"Castle Town Dandelion" is a slice-of-life comedy anime centered around the Sakurada family, who reside in a modern-day kingdom. The family consists of nine siblings, each possessing unique supernatural abilities, and their father, who serves as the king. The twist lies in the fact that the next monarch is to be chosen through a democratic process, with the citizens voting for their preferred candidate among the siblings. The entire kingdom is under constant surveillance through thousands of cameras installed across the town, broadcasting the siblings' daily lives to the public as part of the election process.

The story primarily focuses on the interactions and dynamics between the siblings as they navigate their daily lives while being scrutinized by the public. Akane, the third eldest sibling, is the central character. She possesses the ability to manipulate gravity but is extremely shy and struggles with her fear of being watched. Her siblings include the responsible eldest brother, Shū, who can create clones; the cheerful and athletic second sister, Misaki, who has super strength; and the mischievous fourth sibling, Haruka, who can teleport. Other siblings include the quiet and bookish Hikari, who can manipulate light; the playful and energetic Kanade, who can communicate with animals; the stoic and reserved Aoi, who can control time; the youngest sister, Teru, who can control electricity; and the youngest brother, Shiori, who can manipulate memories.

The narrative explores how each sibling balances their personal lives, aspirations, and relationships with the pressure of being potential royal candidates. The series delves into their individual struggles, such as Akane's efforts to overcome her shyness, Shū's burden of responsibility as the eldest, and Misaki's desire to be seen as more than just a strong athlete. The siblings often find themselves in humorous and heartwarming situations, whether it's dealing with school life, family bonding, or unexpected challenges brought on by their powers.

Throughout the series, the siblings' interactions with each other and the townspeople highlight their growth and development. The story also touches on themes of family, responsibility, and the complexities of living under constant public scrutiny. While the election looms in the background, the focus remains on the everyday lives of the Sakurada siblings, offering a blend of comedy, lighthearted moments, and occasional heartfelt scenes. The series concludes with the election results, but the emphasis remains on the familial bonds and personal growth of the characters rather than the political outcome.