The great detective Akutabe has an assistant, Rinko Sakuma, who is trying to learn to summon demons. This is the story of her misadventure when she actually manages to summon 2 demons unexpectedly. (Source: ANN)

This is simply the OVA summing up the major events and battles of Initial D 4th Stage much like the Initial D Battle Stage original summed up the first 3 seasons. Additionally, has 2 extra battles from the manga that were not incorporated into the original 4th Stage. (Source: ANN)

For the last three years, Clay has undergone rigorous training in order to find her father, who was last seen exploring a dungeon. While dungeon exploring is difficult for any regular adventurer, Clay knows her father, a thief who doesn't purely rely on raw power or magic, managed to progress farther than anyone else. Clay sets off after him, following in his footsteps until she encounters a furnished room behind a dungeon wall. Clay is shocked to find the room is filled with monsters that can talk and a girl who claims to be the dungeons administrator. However, the room is meant to be kept hidden from explorers. Now that she knows the secret behind the dungeon, Clay is hired to be part of their staff. While she never expected to find a job in her adventure, doing so may just help Clay unravel the mystery behind her father's disappearance.

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.