History Fridge / HighSchoolDXD

* In EP 1 of S1, while Issei and Raynare are clothes shopping, among all the t-shirts he is shown looking at, a muscled shirt with [[Manga/FistOfTheNorthStar Seven Scars]]. Suddenly, his dress break specializing women's clothes makes far more sense.

* It comes off as a funny joke that Akeno suddenly gains a massive boost in power once Issei promises to go on a date with her, but it actually makes sense. She is a devil a creature of desire the thought of having her desire fulfilled allowed her to draw on that for strength. Same with Rias the thought of what is 'hers' being taken away infuriates her, remember what she said when Issei almost died. 'how dare you take away what's mine.' not the man I love or my friend but what's 'Mine' even if she does care for them it is subtle reminders like that, that remind you they aren't humans but devils.

[[AC: FridgeLogic]]

* Xenovia's intention is to bear Issei's child. [[DidntThinkThisThrough So why is she carrying around condoms?]]
** She only directly tried bearing his children in the episode she surprised him in - Issei's freaked-out reaction was summed up as (paraphrased): "Do you understand what you're saying!? You wanna make a baby!? That's insane! That's insane! That's insane!". And not only that, this attempt indirectly caused agony to Issei, due to the beating that resulted from the misunderstanding (something she certainly wouldn't seem to be all for). So as a result, she likely decided to put the baby-making on hold for now until Issei said/showed it was okay - hence the condoms, and the 'we can practice anytime' aspect. Becoming a Devil also means she's got plenty of time to wait now, since most live 'almost forever'

* It's not usually noticeable since she usually wears her hair in a ponytail, but when Akeno appeared for her date with Issei, [[LettingherHairDown her hair is down]]. Aside from bangs and hair color[[labelnote:*]]Both appear to be black with different tint colors.[[/labelnote]], she looks a bit like [[BastardGirlfriend Raynare]]. Also has a bit of FridgeHorror due to her fear of revealing herself as a Fallen Angel to Issei and him hating her for being one.

* Cao Cao being CrazyPrepared in general but especially Volume 11. Let's face it, if you were a PlayerCharacter and you're up against an armada of demons and angels and you're target is to take the power of the strongest dragon aka your PuppetKing, wouldn't ''you'' wanna be CrazyPrepared for the situation by collecting all the [[InfinityPlusOneSword Infinity Plus One Swords]] and an assortment of [[GameBreaker Game Breakers]] just to even stand a chance against them? Even Azazel notes that they're the [[FinalBoss Final Bosses]] for the humans in video game terms.

** Considering he was already CrazyPrepared, just what did he do to get one of Medusa's eyes?
* More of a Meta FridgeHorror. Due to the anime, as mentioned on the [[YMMV/HighSchoolDXD YMMV page]], a popular fanon theory is that Rias deliberately let Issei die so she could recruit him. This brings another person to mind: [[BitchInSheepsClothing Diodora]] [[SmugSnake Astaroth]]. Essentially, Rias succeeded with Issei what Diodora wanted to do with Asia. Good thing this is only fanon.

* Sirzechs in the last episode of the anime seems content that Issei took Rias away from the engagement ceremony and even Grayfia notes that he seems happy about the fact that it's "unfortunate" that the Gremory and the Phenex clan will not have any marriage whatsoever. The reason why he's happy about it is because it reminded him of his and Grayfia's circumstance when he married Grayfia, one of the servants of the Old Lucifer and at that time, it was a big no-no.

* Sirzechs in the last episode of the anime seems content that Issei took Rias away from the engagement ceremony and even Grayfia notes that he seems happy about the fact that it's "unfortunate" that the Gremory and the Phenex clan will not have any marriage whatsoever. The reason why he's happy about it is [[spoiler: because it reminded him of his and Grayfia's circumstance when he married Grayfia, one of the servants of the Old Lucifer and at that time, it was a big no-no.]]

** Considering he was already CrazyPrepared, just what did he do to get one of Medusa's eyes?

* Vali in the eleventh episode of [=NeW=] did not make his Divine Dividing appear to block Gasper's [[TimeStandStill time stopping ability]] while he lampshaded that he and Issei were able to block it using their dragon powers (Issei had to make his gauntlet appear). The reason? He did not tap into Albion's power, but instead used the magic reserves he inherited from the original Lucifer. Becomes something of ForeShadowing, as later he was revealed to be a direct descendant (or more accurately, the great grandson)

* Issei gaining his King status not only from his high power but also showing he has qualities as a King.A TookALevelInBadass for the Harem King.
** Issei protected his own thus gaining the love from Rias, Asia and Rossweisse.
** Issei showed wisdom to accept one despite past affiliations/relation with an enemy faction which allowed Akeno and Ravel to fell for him.
** AsskickingEqualsAuthority is a trait that Xenovia fell on.

* Vali in the eleventh episode of NeW did not make his Divine Dividing appear to block Gasper's [[TimeStandStill time stopping ability]] while he lampshaded that he and Issei were able to block it using their dragon powers (Issei had to make his gauntlet appear). The reason? He did not tap into Albion's power, but instead used the magic reserves he inherited from the original Lucifer. Becomes something of ForeShadowing, as later he was revealed to be a direct descendant (or more accurately, the great grandson)

** Issei showed wisdom to accept one despite past affiliations/relation with an enemy faction which Akeno and Ravel fell for.