The anime version of No. 6 is an adaption of the novels. It has eleven episodes and one season.
The story takes place in an ideal city known as "No. 6", where Shion, a boy raised in the elite and privileged environment of his home, gives shelter to another boy, who only goes by the name 'Nezumi', during the former's 12th birthday. After spending a rainy night with his new friend, the next morning Shion wakes up to discover that Nezumi has left and disappeared without a trace.
Four years after the events on Shion's birthday had taken, he experiences a spate of incidents around him in which a deadly infection spread by parasitic wasps, would its leads victim to age rapidly. One of the people who had fallen victim to this deadly infection was Shion's co-worker. As he had dropped dead in the middle of the day during his shift with Shion, the latter is arrested under the suspicion of murder. Whilst the accused party is being transported to the Correctional Facility, Nezumi appears and rescues him. Soon after his grand escape, Shion begins to find out the hidden truth behind the supposedly 'Ideal' City No.6.
List of No.6 Episodes
Main Article: List of Episodes