Issei prepares for his school trip to Kyoto, but before he leaves, he must go with Rias and the others to the Gremory household so Rias can report the completion of her family. There, they meet Sairaorg, who requests a little hand-to-hand with Issei.

Issei and his team meet with Cao Cao at the Nijo Castle and find Kunou's mother there. A showdown between the two factions begins. Pushed into a corner, Issei finally finds it inside himself to unleash his inner potential and call for what is his.

Issei Hyodo's first date with his new girlfriend ends poorly when she turns into a monster and stabs him in the stomach. Luckily, he's saved by Rias, the buxom president of his school's Occult Research Club. And then, things really start to get weird...

Surprise! All the members of the Occult Research Club are devils, including new-recruit Issei, who's having difficulties figuring out the whole "demonic power" thing. Maybe he'd have better luck if Fallen Angels stopped popping up and trying to kill him.

Summer break is coming up fast for Hyodo Issei, but all his plans are put on hold when he finds out he is to accompany Rias for her visit back home to the underworld! A new adventure is about to begin and all the while Koneko is not acting herself.

Issei dreams that he is marrying Rias, which leads him to get in touch with his inner dragon. Asia confesses a desire to have a deeper relationship with Issei.

Issei and Asia undergo a special training camp with the other household members to get ready for the upcoming Rating Game. Issei struggles to figure out what his own special characteristic is. Rias explains more about devils and the Gremory family.

New living arrangements are made for Asia, who has been living in the club's room. Meanwhile, Issei begins a new training regimen with Rias to improve his physical fitness. Asia begins attending school, where she is placed in Issei's class.

The Kuoh Academy students fight Kokabiel and his minions to defend their school and their town.

The Occult Research Club fights Kokabiel and learns some shocking truths about the power struggle between the angels, fallen angels, and devils.

The Occult Research Club takes over cleaning the pool to thank the student council for their help with Kokabiel, and Issei runs into a lot of trouble.

Issei meets and befriends a girl named Asia Argento, a Sister who has arrived to serve at the town's church. Issei learns more about the chess game in which he has become a part, and the roles that he and his fellow devils play within it.

Rias decides that it is time for Issei and Asia to have servant familiars. The school's student council visits the club room, and Issei learns that they are another faction of devils. The two groups compete to see who gets first pick of the new familiars.

Asia saves Issei by healing the dragon within him after his incomplete transformation. Finally, they all make it back home and enjoy their peaceful days. After Loki fails with Issei, he turns his evil grasp toward Rias.

Issei gets another warning about the white dragon, and church followers bearing Holy Swords pay a visit to the devils.

Issei and Kiba fight the Xenovia and Irina, and Issei tries to deal with the consequences of their fight.

Issei and the others team up with the church to fight Freed, but an even greater enemy appears.

Issei and the others begin their training to improve each of their skills. All the while things are happening around them as powerful people gather to fight against the Chaos Brigade. All the young devils gather in one place.

Issei and the others are back to school and their daily lives. Irina and Rossweisse both start to live at Issei's house and the sports festival is fast approaching. During all of this, Diodora Astaroth appears before Asia and proposes to her?!

Alternative version of the final four episodes of High School DxD BorN.

The Hero Faction has arrived and Cao Cao wants to cross blades with Azazel and the Red Dragon Emperor. In such a dire situation, Issei must respond quickly so all his friends make it out of this alive. Will he ever find his "potential" and release it?

The Chaos Brigade has quieted down since their stunt in Kyoto so Issei and the others must now focus on other issues. After all, there are hero shows to act in, a school festival to prepare for, and the ever-looming Rating Game with Sairaorg...

The Rating Game is about to start, but Issei has things to figure out. He has formulated a guess as to why Rias is acting the way she is, but does he dare believe it? His girls give him courage. And, finally, their team steps out into the battlefield.

Issei is back with Rias and Asia living in his house, and Kiba starts acting weird when he sees a picture of a holy sword at Issei's house.

Diodora continues to pester sweet Asia as the Rating Game approaches. Issei and the others prepare for battle as dark things brew in the background. When the Gremory household jumps to the field, they find themselves in an unexpected battle!