Other Characters

Minor recurring characters in High School DxD.

Mr. Hyoudou
Voiced by: Mitsuru Ogata

Issei Hyoudou's father and an ordinary office worker. He has unofficially adopted Asia as a second child and supports Issei's relationship with Rias.

Mrs. Hyoudou
Voiced by: Sachiko Kojima

Issei's mother and a full-time housewife. She is an excellent cook and sometimes goes out to a part-time job. She has unofficially adopted Asia as a second child and supports Issei's relationship with Rias.

Morisawa
Voiced by: Tsuyoshi Aoki

Morisawa (森沢) is a regular client of Koneko and later Issei. He is a lolicon who likes to dress Koneko in various cosplay outfits. Like Issei, he is a huge fan of Dragon Ball (Drag So-Ball in the Anime).

Mil-tan
Voiced by: Kenta Miyake

Mil-tan (ミルたん Miru-tan) is another one of Issei's regular clients, a male bodybuilder who wishes to become a magical girl. He ends his sentences with "Nyo" (にょ).

Past Possessors of the Boosted Gear
The past possessors of the Boosted Gear whose consciousness are all stored within the Boosted Gear. Only two of the past possessors are named.

Belzard
Belzard (ベルザード Beruzādo) was a man known as the strongest possessor, defeating two White Dragon Emperors in his lifetime. He appears in Volume 9, singing the Oppai Dragon song lyrics before disappearing.

Elsha
Elsha (エルシャ Erusha) was a woman known as the strongest female possessor. She appears in Volume 9 alongside Belzard inside the Boosted Gear, providing Issei the "box" to tap into the full power of the Red Dragon Emperor. Her consciousness disappears soon after.

Other Possessors
Among the past possessors, there is a young man around the same age as Issei who was killed by another Longinus user after succumbing to the effects of Juggernaut Drive.

As of Volume 12, all the consciousness of the past possessors have disappeared from within the Boosted Gear after they sacrificed themselves to save Issei's soul which was on the verge of breaking down after receiving Samael's curse.

Momo Momozono
Voiced by: Risa Tsubaki (TV Momo), Arisa Noto (Alarm Clock Momo)

An anime-exclusive character, she is an adult video actress who portrays the tokusatsu heroine Kaben Rider Pinky (花弁ライダーピンキー Kaben Raidā Pinkī?, lit. "Pedal Rider Pinky", based on the Kamen Rider Series). Issei, Matsuda, and Motohama are all huge fans of her. She appears in the first episode of the anime where the Perverted Trio are watching Kaben Rider Pinky, and in the last episode as one of the various characters featured on Issei's alarm clock (albeit voiced by a different actress).

Susan
Voiced by: Ayako Kawasumi

One of Issei's clients who appeared in the side story "The Work of a Devil", an American college student donned in samurai armor who is studying abroad.

Horii
Voiced by: Shinobu Matsumoto

Susan's lover, a man donned in knight armor. Appeared at the end of the side story "The Work of a Devil".

Shuri Himejima
Shuri Himejima (姫島 朱璃, Himejima Shuri) was Akeno's mother and Baraqiel's wife. A priestess (miko) coming from a well-known shrine, Shuri saved Baraqiel's life when he was injured, and later fell in love with him. However, her relationship did not go well with her family, as they believed that she had been brainwashed by the Fallen Angel. To that end, her family sent well-known practitioners to dispatch the Fallen Angel and bring her back. They were defeated by Baraqiel, but some of them held a grudge against Baraqiel and told the faction who were against the Fallen Angels at the time about his location. Shuri was killed defending Akeno when several of Baraqiel's enemies attacked her home while the latter was away, resulting in Akeno's hatred towards her father for not protecting her mother. She returns as an apparition in Volume 7, encouraging her daughter to reconcile with Baraqiel as she knows that he still greatly cares for and loves them, before disappearing. It is revealed in one of the side stories that Shuri was a sadist like her daughter, and engaged in SM acts with her husband every night.

Unnamed Hero Faction Member
A member of Khaos Brigade's Hero Faction with the Sacred Gear Night Reflection. He first appeared in Volume 7 combating the Gremory Team. While he lost to Issei, his frustration on losing allowed him to achieve his Balance Breaker, Night Reflection Death Cross and he was teleported away by the Hero Faction before he could be captured by the Gremory Team. He later reappears in Volume 9 where he faces off against Issei in a rematch, losing to him once again.

Zatouji
Voiced by: Hisao Egawa

Zatouji (ザトゥージ Zatūji) is a young Devil-in-training from Madara Town who specializes in familiars. He strives to become a Familiar Master. He acts as a guide to novice Devils who have yet to obtain a familiar. He suggests capturing several of the same type to breed them in order to gain more powerful familiars. In the anime he is depicted as a middle-aged man.

Gentleman Alchemist
Voiced by: Itaru Yamamoto

The Gentleman Alchemist (錬金術師の紳士 Renkinjutsu-shi no Shinshi) is an unnamed Stray Devil who appears in the OVA episode "I'm Harvesting Breasts!" He was captured by the Occult Research Club and interrogated by Grayfia, who revealed to the Occult Research Club that he created the Breast Chimera so that every flat-chested girl in the world would have large breasts.

Breast Chimera
The Breast Chimera is a creation of the Gentleman Alchemist that appears in the OVA episode "I'm Harvesting Breasts!" It is a plant with Dragon-like features, and has the ability to produce breast-like fruits by feeding off of the spiritual energy from women's breasts, specifically the much bigger ones like Rias' and Akeno's. According to Grayfia, the Gentleman Alchemist created the Breast Chimera so that every flat-chested girl in the world would have large breasts by eating its fruit. It was defeated by Rias' boosted Power of Destruction.

Reynaldo
Reynaldo is the conductor of the Gremory private train. He was introduced in the beginning of Volume 5 when Rias and her peerage journeyed to her home in the Underworld so that she could participate in the Young Devils Gathering and introduce her new servants to the Gremory household. He is described to be a gentle looking old man with a dandy white beard and hat.

Naud Gamigin
Naud Gamigin (ナウド・ガミジン Naudo Gamijin) is a member of the House of Gamigin from the 72 Pillars. An announcer of the Underworld media, he was one of the announcers during the Rating Game between Sairaorg and Rias.

Rudiger Rosenkreutz
Rudiger Rosenkreutz (リュディガー・ローゼンクロイツ Ryudigā Rōzenkuroitsu) is a former human that was reincarnated into an Ultimate-Class Devil and is the current 7th ranker in the Rating Games.

Lilitifa Wepal
Lilitifa Wepal (リリティファ・ウェパル Riritifa Weparu)

Gragg Forneus
Gragg Forneus (グラッグ・フォルネウス Guraggu Foruneusu)

Eneely Vassago
Eneely Vassago (エニーレィ・ヴァサーゴ Enīryi Vasāgo) is the elective head and next heiress of the House of Vassago. The House of Vassago originally had good ties with House of Astaroth until their downfall. Due to that, they have a grudge against Rias Gremory and her group.

Iolava Amon
Iolava Amon (イオラヴァ・アモン Iorava Amon) is the second son of the House of Amon, and the fiancé of Eneely Vassago. He looks down on Low-Class Devils, but is also perverted. He created a Cerberus which can use a long-range Dress Break after witnessing the beauty of Issei's Dress Break.

Trivia

 * Drag So-Ball is based off of Akira Toriyama's hit manga Dragon Ball. In addition, Satoru Soramago, Dells, and the Goki Dama are all based based off of Son Goku, Frieza, and the Spirit Bomb (Geki Dama) respectively.
 * The Familiar Master, Zatouji, is a parody of Ash Ketchum/Satoshi of Pokemon/Pocket Monsters fame, right down to his catchphrase "Get da ze!" (Gotta catch 'em all!) and even his appearance in the anime.
 * In the Afterwords for Volume 8, the author reveals that he is a fan of Pokemon and that he wrote the story "The Familiar's Requirement" as a request from the illustrator, Miyama-Zero.
 * In the anime, Zatouji looks like an old man, unlike his light novel original who was meant as a young man.
 * The Gentleman Alchemist bears a striking resemblance to Count Dracula.