The other Bishop of the House of Gremory is released, and Akeno takes Issei to meet a new acquaintance.

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...

Issei summons his beloved President into the heat of the battle in Kyoto. As she floats before him, Elsha whispers into his ear to poke her boobs. Pressing the switch releases his potential power and Issei challenges Cao Cao once again.

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.

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.

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?!

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.

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.

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

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.

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 goes to see Vali for help, which is in itself an action against the underworld. With the help of Arthur and his Holy Royal Sword Collbrande, the Rias household goes to the Dimensional Gap. There, they meet Rias and try to bring her back.

Issei and the others continue their training, even while they fully enjoy themselves in Kyoto. Issei's group meets the mysterious nine-tailed fox once again and, this time, she begs them to help the youkai save her mother from the Chaos Brigade.

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.

The Gremory family is now in full training mode for the upcoming Rating Game. However, Issei has a lot of other things on his plate. There's a school festival to prepare for and a press conference to overcome. On top of that Rias is acting strange?!

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.

Issei meets Michael, the Chief of the Angels, and continues training Gasper in the days leading up to the Leaders' Summit.

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.

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!

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?

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

Issei learns more about the feud between the Twin Sky Dragons and Rias and Sona have to deal with troublesome family members at Open House.

With Loki defeated, Rias and her household return to the human world to finish up their last days of summer. A pile of homework awaits Issei, but he goes on a date with Akeno instead! Akeno throws herself at Issei, hoping to forget her terrible past.