"Knights of Ramune" is a six-episode OVA series that blends science fiction, fantasy, and comedic elements. The story is set in a futuristic universe where the galaxy is under threat from the Space Pirate Hysteria, a malevolent force seeking to conquer planets and spread chaos. The protagonist, Cacao, is a young boy from the peaceful planet of Cacao, which is known for its production of the titular Ramune soda. Cacao is chosen by the Galactic Police to become a Space Knight, tasked with protecting the galaxy from Hysteria's destructive plans.

Cacao is joined by his companions, the energetic and resourceful Princess Milk and the stoic warrior Vanilla. Together, they form a team dedicated to combating Hysteria's forces. The narrative revolves around their missions to thwart the pirate's schemes, which often involve bizarre and humorous situations. The series incorporates a mix of action, slapstick comedy, and lighthearted moments, with a focus on the quirky dynamics between the characters.

Hysteria's plans frequently involve targeting planets with unique resources, such as the Ramune-producing Cacao, which serves as a central element in the story. The series explores themes of friendship, bravery, and the importance of standing up against tyranny, albeit in a comedic and exaggerated manner. The episodic structure allows for self-contained adventures while maintaining an overarching narrative of the team's efforts to protect the galaxy.

The characters are designed with distinct personalities and roles. Cacao, despite his initial reluctance, grows into his role as a Space Knight, embodying determination and a sense of justice. Princess Milk provides comic relief with her over-the-top antics and unwavering enthusiasm, while Vanilla offers a grounded, serious counterbalance to the group's dynamic. Hysteria, as the antagonist, is portrayed as a flamboyant and eccentric villain, adding to the series' comedic tone.

"Knights of Ramune" combines its sci-fi setting with a playful approach to storytelling, creating a series that is both entertaining and accessible. The blend of action and humor, along with its colorful cast of characters, makes it a distinctive entry in the genre.