Ranjo Riku

The story revolves around a typical high school boy named Kakeru Daichi and the can of melon juice soda that he bought from a vending machine. The can suddenly transforms into a beautiful but standoffish girl that Kakeru nicknames "Melon," and more "Akikan" \["empty can"] girls appear. However, Akikan girls need to be infused with carbon dioxide from kissing to survive. See AnimeNewsNetwork for the anime. See AnimeNewsNetwork for the OAV.