Rias brought Issei back to life at the expense of all her pawn Evil Pieces when Raynare murdered him, seeing this potential in him, she attempts to train him to become a better Devil despite being initially weak. Rias has a lot of affection towards Issei from the start of the series, which seemed to have grown as the series progressed. This is highly attributed to the Gremory's tendency to have close relations with their servants as compared to other clans. Rias doesn't seem to mind allowing Issei to gaze on her naked body. While in the beginning Rias saw him more of a younger brother she loved teasing, following events of Volume 2 when upon seeing him go through so much against Riser to null her engagement, Rias falls madly in love with Issei and gives him her first kiss, soon after she now attempts to keep him away from the other girls who may have affections for him.
High School DxD - Rias Gremory e Issei Hyoudou | Dxd, Highschool dxd, Anime high school
High School DxD just put the finishing touches on its fourth season, and fans are definitely happy to see where the season wrapped things up as Issei and Rias took a new step in their relationship. What was that step? It's the fact that they finally have an actual relationship now. After seasons of misunderstandings and one-sided confessions, Rias and Issei finally confirmed their love for one another by episode's end. After Issei defeats Sairaorg in the final battle of the rating game, Rias sees that his new "Queen" upgrade to the Red Dragon Armor is the same color as her hair. With this, he finally accepts that he loves Rias, something he's been avoiding throughout the season thus causing the initial rift between the two of them. But after the battle ends, Rias and Issei fully confess their feelings for one another.
Issei has developed many relationships throughout the series, both within the Occult Research Club and the Three Factions. He has also attracted the attention of most of the female characters. Rias is the woman who reincarnated Issei after Raynare killed him and the woman he loves.
This page contains spoilers of the following fanon; Read at your own risk ". He is the son of both Issei Hyoudou and Rias Gremory, as well as one of the two eldest siblings of seven children, being the second oldest child. He is a wielder of the Sacred Gear, X-Gear Booster, thereby making him a dangerous opponent to underestimate.