A soda can girl needs you to carbonate her by mouth, and the show commits completely to this premise without blinking. The entire OVA is built around watching a high school boy and his beverage girlfriend navigate the most absurd intimacy ritual anime has ever treated as normal. It's fanservice that knows exactly what it is, refuses to apologize, and somehow makes the ridiculous feel inevitable.

Kakeru Daichi is an ordinary high school boy until a can of melon soda he gets from a vending machine turns into a pretty but aloof girl, whom he calls Melon. More Akikan girls soon appear, and each of them needs carbon dioxide to take human form. In this single OVA episode, the Akikan and their owners head to a hot spring to unwind and enjoy themselves. Relaxation proves hard to come by, because Kakeru can't keep his lecherous streak in check around the girls. The result is a short ecchi comedy built on bathhouse mischief. The DVD came packaged with a special edition of the ninth light novel volume.