Haruki Nakano lives an average high school life, except for the fact that his mother is overseas and he shares an apartment with his four sisters. There's the oldest, Mutsuki, who has a bad habit of falling asleep in his bed, the junior high school student Yayoi, who hits him whenever something happens, and then the grade school twins, Uzuki and Satsuki, who love to play pranks on their older brother. Stuck in a house with four girls, Haruki has to deal with all sorts of trials. From going grocery shopping, watching scary movies, to kissing practice, life is never boring in Danchigai!

Hacka Dolls are AI that scan a person in order to tailor news recommendations and information to their users. These widespread, personalized robots have served many citizens, from government officials to professional sports players. A severe drop in quality leads to the production of three substandard Hacka Dolls. Due to their personality defects, they are sent to Earth, tasked with advancing humanity in whatever way they can. Whether it be encouraging a fujoshi to sell a doujinshi at Comiket or performing in an idol group, the three dolls will complete any task as long as it abides by their moral compass. Despite their shortcomings, they take their mission very seriously and always try their best to assist everyone with incredible enthusiasm.

60 years ago, a strange case of insomnia struck the population, forcing them to stay awake for more than a full week. The victims, completely sleep deprived, all went mad. To cure this illness, a new medicine was produced, but the side effects turned the patients into vampires. Humanity went to war against this new species and triumphed, but some of the vampires managed to survive. Born from a Human and a Vampire, the main character Mi Liu, "The Child of Hope," is to represent the new hope that will connect the two species. Ringleader of a bank robbery, Mi Liu is arrested and transferred to a special prison of the National Defense Agency that monitors Vampires. Trying to break free with Anji, Mi Liu is attacked by strange monsters and he finds out that the prison location corresponds to the birthplace of Vampires, the old capital "Blue Town." Why are Vampires trapped in Blue Town? What are those strange monsters attacking them? Our heroes must fight to solve those mysteries. (Source: Emon via ANN)

Unaired episode of Danchigai included on the Blu-ray/DVD volume.