"Akikan!" is a 12-episode anime series that blends comedy, romance, and light science fiction. The story revolves around Kakeru Daichi, a high school student who accidentally becomes involved in a bizarre experiment involving anthropomorphized soda cans. These cans, known as "Akikan," are ordinary beverage containers transformed into human-like forms when their tabs are pulled. The experiment, conducted by a mysterious organization, aims to determine whether steel or aluminum cans are superior by pitting Akikan against each other in battles.

Kakeru's life takes a turn when he purchases a melon soda can, which transforms into a spirited girl named Melon. As an aluminum Akikan, Melon requires regular doses of carbon dioxide to maintain her human form, which she obtains by drinking soda or through direct contact with Kakeru's breath. The series explores the growing bond between Kakeru and Melon as they navigate their unusual relationship. However, their dynamic is complicated by the arrival of other Akikan, including Yell, a steel can who becomes a rival to Melon. Yell forms a connection with Kakeru's friend, Najimi, further entangling the group's relationships.

The narrative progresses as the Akikan engage in battles to prove the superiority of their respective materials. These confrontations are often comedic and lighthearted, with the series emphasizing the quirky and absurd nature of the premise. Alongside the battles, the story delves into themes of identity, companionship, and the meaning of existence, as the Akikan grapple with their purpose and humanity. The series also introduces additional characters, such as the eccentric scientist Dr. Shidō, who oversees the Akikan experiment, and other Akikan like Ginger Ale and Budweiser, each with distinct personalities and motivations.

While the plot primarily focuses on the interactions between Kakeru, Melon, and the other Akikan, it also incorporates elements of slice-of-life and romantic comedy. The series balances its fantastical premise with moments of everyday humor and heartfelt connections, creating a unique blend of genres. Despite its unconventional concept, "Akikan!" maintains a straightforward and accessible narrative, appealing to viewers seeking a mix of comedy, romance, and light action.