Akikan!

Akikan! (アキカン!) or Empty Can! is a light novel series written by Riku Ranjō and illustrations by Hiro Suzuhira. The novel was published up to 8 volumes by Shueisha under their Super Dash Bunko label from May 24, 2007 to April 24, 2009. A manga adaptation began serialization in Ultra Jump on October 18, 2008. An anime adaptation aired from January 3, 2009 to March 28, 2009, followed by an OVA that was released on October 23, 2009, until they have been licensed by Sentai Filmworks.

Plot
The story focuses about a group of anthropomorphic drink cans who do battle. One day, a high school student named Kakeru Daichi discovers a magic melon soda can that can transform into a human girl. More "akikan" girls begin appearing after another, and each needing to be infused with carbon dioxide from their respective drink types to survive. They were created as part of the 'Akikan Elect' to determine whether steel cans or aluminum cans are superior, and must battle each other until only the strongest type is left standing.