High School DxD - Season 4 (2018)

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.

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 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 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.

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 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?!

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.

The Game has officially begun and the dices keep rolling. One by one various members of each family fight and slowly retire from the Game. Everyone in the Gremory household is risking their lives and fighting desperately to bring Rias victory.

Sairaorg has finally risen up to the stage and Kiba, Xenovia, and Rossweisse team up against him. The battle is swift and brutal and Issei is finally reaching his bursting point. Will he be able to channel his feelings? Or will resentment take over?

Issei purges the curse of his Sacred Gear and stands up once again, in his form as a Queen piece. Sairaorg and Issei duke it out in one final fist fight where winner takes all. After that, the only thing he has to worry about is his confession to Rias...