The story of the series follows Koinu, a serious-minded dog who goes to work one day only to find that his company has gone bankrupt. At a loss, Koinu takes a job from a mysterious recruitment agent and is hired to paste dog stickers all over the city. Even though he doesn't understand the purpose of this strange assignment, Koinu works hard every day at his new employment.
In the fallout of nuclear war, the last of humanity survives with the help of life-like androids known as Dolls. Built to serve, some fight in wars as Tactical Dolls or T-Dolls. Now, an elite team comprised of T-Dolls are sent to face a new rogue threat, Sangvis Ferri. Leading them into battle is their new human commander, M4A1.