Main Characters
Issei Hyoudou
Ravel did not think much of Issei when they first met, but she started to admire him after he defeated her brother Riser to get Rias back. She was shown to have developed feelings for him by Volume 5 and have fallen in love with him by Volume 12, cemented by her feelings of grief and sadness over his 'death' and her happiness at his return. It is implied in Volume 9 that she enrolls in Kuoh Academy so she can get closer to Issei and moves in with him in the following volume. She happily accepts Sirzechs's request of becoming Issei's manager and continually works hard for him, such as finding a suitable magician for him to make a pact with. She also constantly fights with Koneko over who gets to sit on Issei's lap. Ravel explains at the end of Volume 14 that the reason why she grew to admire and later fall in love with Issei was because of stories her servant used to tell her as a child. These stories were about heroes who sacrificed or suffered greatly in order to protect people and the ones they love. As Ravel grew, she gradually forgot these stories, but recalled them after seeing Issei getting hurt, beaten, and eventually winning in order to save Rias. She then began to research more about him, learning that despite his perverseness, he cares about his friends and family and how much he resembled the heroes that her servant used to tell her as bedtime stories. It then grew to the point where she wanted to get closer to him, to her fully realized hero and idol, and support him as the person she respects and developed feelings for.
In Volume 22 upon Issei's promotion to High-Class, Ravel's mother approaches Issei to remind him of the promise they made about allowing Ravel to join his peerage. Ravel is then traded to Issei, becoming his second official Bishop.
In Volume 23, Ravel became bolder after becoming a member of Issei's peerage, such as shyly expressing her desire to sleep with him while Rias and Akeno aren't around and wearing a transparent white negligee and having him grope her. She has even stated a desire to be the object of Issei's perverted desires, stating that her mind and body belonged to him, her King, this caused Issei to have a lewd fantasy about her letting him grope her breasts. She's more determined as she allows him to touch and squeeze her breasts and fights with Church Trio for his affections and who gets to sleep with him. Ravel appears to be Issei's second in command, as well as his mentor in his peerage due to her experience as a High-Class devil. Ravel's mother has even encouraged Issei to fully utilize Ravel's potential. Despite Ravel's strict nature as his manager and peerage member, Issei has shown complete trust in Ravel's judgement, due to her experience. Ravel is deeply saddened by her team's loss to Dulio and his team of Angels, feeling she let Issei down and cried deeply, but was hugged and comforted by Issei, who assured that they would become stronger and took Ravel away from everyone else to console her and hear her emotions. Millarca has even noted that Issei deeply treasures Ravel, showing how close the two of them have become.
In Volume 24 after fighting off the Grim Reapers, Ravel unhesitatingly allowed Issei to use her breasts to contact Koneko and Kuroka. As Issei squeezed her breasts Ravel moaned blissfully, showing pleasure in being the object of Issei's perverted technique.
In Volume 25, Ravel was present when Issei's future brides fought over him and despite trying to manage the situation, Ravel eventually joined the fight herself.
Koneko Toujou
Ravel and Koneko have a hot and cold relationship due to the fact that she is a Phoenix and Koneko is a Nekomata, alluding to the natural discord between birds and cats. They see each other as rivals because both are in love with Issei, and will openly compete with each other for his affections. However, they have been shown to get along and have become friendlier to each other as time goes on, usually only showing hostility to one another when it involves Issei, such as in Volume 14, where they are shown to be fighting over the spot on Issei's lap. Koneko is also hinted to feel inferior towards Ravel due to her larger breasts, feeling Issei prefers Ravel over her, despite Issei's insistence that he cares for them equally.
Rias Gremory
While originally the two didn't have much of a close relationship, Rias was later put in charge of Ravel who transferred to Kuoh Academy in order to grow closer to Issei. The two have become quite close as seen when they organized a rematch between Rias' and Riser's peerages over tea. Ravel is shown to greatly respect Rias' standing as Issei's legal wife as she helps her manage the rest of the girls who are in love with Issei.
Phenex Clan
Lady Phenex
Ravel is Lady Phenex's only daughter among her four children, as well as being the youngest. Lady Phenex is quite aware of Ravel's love for Issei and her desire to be useful to him in any way. She has also traded Ravel from her son Riser's peerage for an unused Bishop piece, and has gone on to tell Issei that Ravel is currently a "free" Bishop.
Ruval Phenex
Ruval is one of Ravel's three older brothers, he being the oldest of the three. He is seen with Riser trying to cheer up Ravel after she had learned Issei had "died". He then leaves to fight the monsters created by the Annihilation Maker.
Riser Phenex
Riser is one of Ravel's three older brothers, being the youngest of the three. Originally, Ravel was part of Riser's peerage before she was traded to her mother's peerage for an unused Bishop piece, though it seemed that she herself did not take part much in Riser's Rating Games. The reason Riser added Ravel to his peerage (likewise his harem) was because he had wanted an imouto (little sister) type girl, as well as a tsundere type girl. He also seems to enjoy teasing her about Issei since the two became friends, referring to him as Ravel's future husband, much to Ravel's embarrassment.
Glasya-Labolas Clan
Iryuka Glasya-Labolas
Ravel and Iryuka are old friends due to being classmates since primary school in the Underworld, before Ravel transferred to Kuoh Academy. After reuniting after a while, they appear to be on good terms as Ravel greeted Iryuka with a smile and helped her with establishing her base in Kuoh Town.
Belphegor Clan
Roygun Belphegor
Ravel is shown to have a respect for Roygun due to her status as the former second-ranker Rating Game player, although she gets irritated when Roygun makes advances on Issei. Roygun is also shown to respect Ravel as a strategist and ask for her advice about her rank among of Issei’s harem, and also likes to tease Ravel about her managing skills.
Vampires
Elmenhilde Karnstein
Ravel was initially hesitant to allow Elmenhilde to join Issei's team, but after training her, Elmenhilde was able to join their team. Elmenhilde appears to respect Ravel, even acknowledging her as the team strategist. Ironically, Ravel and Elmenhilde are similar with regards to their relationship with Issei, both of them previously looked down on him, but after witnessing his heroic actions, both fell in love with him.
Dragons
Ddraig
Ravel is shown to greatly respect Ddraig as the Red Dragon Emperor and Issei's partner, as she came up with strategies that he followed during the Azazel Cup.