"Prince Standard" is a manga series that centers on the life of Itsuki Aoi, a high school student who unexpectedly becomes entangled in the world of royalty. Itsuki, an ordinary teenager with a strong sense of justice and a knack for solving problems, is thrust into a position of responsibility when he is revealed to be the long-lost prince of a small European kingdom, Alvandia. The discovery of his royal lineage comes as a shock, as he had been raised in Japan with no knowledge of his heritage. His father, the king of Alvandia, had kept his existence a secret to protect him from political intrigue and potential threats.

As Itsuki adjusts to his new identity, he faces the challenge of balancing his ordinary life in Japan with his royal duties. He is accompanied by a group of loyal retainers, including his childhood friend and bodyguard, Shizuku, and a skilled butler, Klaus, who guides him through the complexities of royal etiquette and politics. The series explores Itsuki's growth as he learns to navigate the expectations of his dual roles, often finding himself at odds with the rigid traditions of the monarchy while striving to remain true to his principles.

The plot delves into the political landscape of Alvandia, where Itsuki must confront rival factions, assassination attempts, and the lingering resentment of those who oppose his claim to the throne. His journey is further complicated by his relationships with other characters, including his half-sister, Princess Lilia, who initially views him as a threat to her own position but gradually comes to respect his determination and compassion. The series also introduces a romantic subplot involving Itsuki and Shizuku, whose bond deepens as they face challenges together.

Throughout the narrative, "Prince Standard" emphasizes themes of identity, duty, and the clash between tradition and modernity. Itsuki's struggle to reconcile his humble upbringing with his royal responsibilities forms the core of the story, as he seeks to redefine what it means to be a prince in a changing world. The manga combines elements of drama, action, and romance, creating a multifaceted tale that explores the complexities of leadership and personal growth.