"It's Summer, To The Underworld Let's GO!" is the first episode of the third season of the High School DxD anime. It aired on April 4, 2015.


Waking up after having his erotic dream turn into a nightmare of Raynare, Issei finds Akeno entering his bed seducing him, before Rias wakes and a bicker ensues between the 2 girls. Overhearing their argument Issei realizes his house was renovated overnight into a large mansion by the Gremory much to his surprise. While eating breakfast, Issei's parents once again thank Rias and her father for the newly renovated house.

On his way to school with the girls, Issei remembers the dream he had in the morning, and vows to Asia that he will protect her regardless of the situation. In school, Issei and his friends discuss their plans for the summer holiday. Inside the clubroom, Rias reveals that she intends to go back to the Underworld and will bring along her servants. Azazel who arrives later also states that he will accompany them back to the Underworld.

Travelling to the Underworld on a train, Gasper and Kiba notices Koneko acting weird. The train then reaches Sitri territory with Sona, Tsubaki and Saji coming to greet the Occult Research Club, thanking Rias for allowing them to use the Gremory Train to go back to the Underworld. After sending Sona and her servants off at the Sitri Territory, the train continues its journey to the Gremory territory. Upon reaching the Gremory territory, the train suddenly stops, Azazel and Rias then comes in and reveal that there will be a meeting with the Norse on countering the Khaos Brigade. The passengers, however, are suddenly teleported into another location without Rias and Azazel. The teleported members are then attacked by a Dragon who appeared in front of them. Deeming the Dragon as their enemy, Akeno takes command over the team and gives out the order to combat the Dragon. Despite their best effort, they are still easily overpowered by the Dragon. Azazel and Rias then intervenes before the battle drags on, revealing that the Dragon, Tannin, is actually a Devil and was asked by Sirzechs and Azazel to assist in the training of the Gremory Team. Ddraig further reveals that he actually knows the Dragon and when asked by Issei on why he said nothing, Ddraig replies that he realizes it was a farce from the start and Tannin wasn't even being serious.

The Occult Research Club under Rias' orders, goes to take a bath first before heading to the Gremory territory where Azazel teaches Issei about poking nipples. Meanwhile Koneko is seen in deep thought while Rias struggles with her troubles that was previously pointed out by Azazel.

Elsewhere, Bikou is seen talking with a girl in black kimono who tells him that she couldn't care less about Loki and is only interested in getting her sister back, murmuring the name "Shirone".


Original airdate: April 4, 2015

Written by: Tetsuya Yanagisawa

Featured CharactersEdit

Three Factions Khaos Brigade Others

Important NotesEdit



Differences between Light Novel and AnimeEdit

  • In the Light Novel, the Occult Research Club was gathered in Issei's room after breakfast, whereas in the anime they gathered in the clubroom. They also did not go to Kuoh academy before the gathering.
  • Official route to the underworld scene, initial check and registration of new members is skipped.
  • In light novel Rias makes her new servants choose a piece of land from Gremory territory for themselves while on train, whereas in anime it is skipped only showing Gremory territory.
  • In the Light Novel, Akeno seductively teases Issei while sitting on his lap. In the Anime, this is replaced by Akeno falling on top of Issei due to the emergency stop.
  • In the anime, Tannin is introduced while the Occult Research Club is on the train, whereas in the Light Novel he is introduced after the gathering of the young devils.
    • Also his appearance in the Anime, a humanoid dragon, is slightly different than in the light novel which is that of a traditional Western Dragon. The appearance of a humanoid dragon is actually the description of another Dragon Grendel whom is the only dragon to have such an appearance.
  • Sona Sitri and her peerage ride along with the Occult research club on the train; in the Light Novel, there was no mention of them on board.
  • In the Light Novel, Azazel throws Issei into the girl's bathing area after his "Pep talk" about nipples. In the Anime this did not happen.
  • In the Light Novel, the bathing scene did not take place until after the Gathering of the Young Devils.

Miscellaneous TriviaEdit

External LinksEdit