The Hyoudou Residence is the home of Issei Hyoudou and his parents. It would later become a base of operations for the allied factions in Volume 5, following the appearance of the Khaos Brigade, as well as a home for all the female members of the Occult Research Club.
The Hyoudou Residence was originally a normal two-story terrace house with a light blue exterior, a balcony on the second floor, and a brown roof. It would later be renovated by the Gremory Clan in Volume 5 of the light novels into a large, six-story house with three large basements.
- First Floor: Includes the living room and kitchen.
- Second Floor: Includes Issei's room, Asia's room, Rias' room, Issei's parents' room, and a bathroom.
- First Floor: Includes guest rooms, the living room, kitchen, a bathroom, and Japanese-styled rooms (washitsu).
- Second Floor: Includes Issei's, Rias', and Asia's rooms, with Issei's room being in the middle. It has two interconnecting doors on each side: one connecting to Rias' room and one connecting to Asia's room.
- Third Floor: Includes Issei's parents' room, a study, and a storeroom.
- Fourth Floor: Includes Akeno's, Xenovia's, and Koneko's rooms.
- Fifth Floor: Not much is known about the fifth floor as of yet, probably includes Irina's, Rossweisse's and Ravel's rooms.
- Sixth Floor: Originally an empty floor, the top floor was converted into a meeting room for the Three Factions (also known as the VIP Room).
- Rooftop: The rooftop is a communal garden decorated with flower plots and there is a small vegetable farm planted. There is also a table and chairs to drink tea at. The rooftop is also home to Ophis' shrine which is located at the corner of the rooftop, which she can use for sunbathing.
- First Basement Floor: Includes a movie theater, training rooms, changing rooms, and a large indoor bath which has a refrigerator filled with three different flavors of milk (fruit milk, regular milk, and coffee milk). A hidden room on this floor also becomes Kuroka's and Le Fay's room. The second hidden room also contains an assortment of baths of various sizes, but are noticeably larger than the first and are decorated gorgeously with ornate patterns, tropical plants, Dragon statues pouring water into the bath, and the Gremory's symbol.
- Second Basement Floor: Includes a heated indoor swimming pool.
- Third Basement Floor: A mostly vacant floor that is generally used for storage. It also includes a library.
All floors in the renovated house are accessible via an elevator. There appear to be hidden rooms in the residence due to the designer of the house having a fondness for hidden rooms. Two of such are located in a corner that leads to a dead end on the first basement floor and at the corner of the bath. The other hidden rooms have yet to be discovered.
- Issei's Parents
- Issei Hyoudou
- Asia Argento
- Rias Gremory
- Akeno Himejima
- Xenovia Quarta
- Koneko Toujou
- Irina Shidou
- Ravel Phenex
- Le Fay Pendragon
- Elmenhilde Karnstein
- Rias' father, Zeoticus Gremory, suggested making it into a palace, but Rias talked him out of it.
- Issei and his father are the only permanent male residents.
- In the manga the first encounter between Asia and Issei's parents (Ch. 11) is in a washitsu-like room, while in the anime they first meet in the living room. This makes it possible that a Japanese-styled room (washitsu) was already present before the renovation by the Gremory Clan.
- Issei's father is only allowed to use the bathroom in the first floor.