The first novel was released on May 24, 2007, and as of April 24, 2009, eight volumes have been published by Shueisha under their Super Dash Bunko label.

[3] At Anime Weekend Atlanta 2011, Sentai Filmworks announced that they had licensed both the TV series and OVA which released in 2012.

More "akikan" girls begin appearing, each of them needing to be infused with carbon dioxide from their respective drink types to survive.

The original light novels written by Riku Ranjō and illustrated by Hiro Suzuhira began release on Shueisha's Super Dash Bunko label from May 24, 2007, with ten volumes released as of October 19, 2015 A manga adaptation illustrated by Momotaro Miyano began serialization in Shueisha's Ultra Jump magazine from October 18, 2008, to April 18, 2009.

The ending theme is "Love Air Recycling" (恋空リサイクリング, Koisora Risaikuringu) by Nomiko (singer) and TECHNOBOYS PULCRAFT GREEN-FUND (music), which has different variations (14 overall) in each episode (including special and OVA) with guest artists sometimes.