This page contains unmarked spoilers. You Have Been Warned!
As much as this series has a lot of funny moments and Fanservice, there are also some scenes that play tug-of-war with your heartstrings.
- Issei's Death by Origin Story at the beginning of the series at the hands of Raynare is tragic. After her Wham Line, Issei has a look of utter horror and betrayal. Despite his perverted nature, Issei's a good and noble young man and he probably still cares that he has his first girlfriend, unaware of what she's really like until he gets Impaled with Extreme Prejudice. Someone he fell in love with tricked and brutally murdered him. And all of this happens before he finds his first real girlfriend in the form of Rias Gremory. Not only that, but it's also the start of his Fantastic Racism against Raynare and the Fallen Angels in general.
- At the end of volume 1, Asia dying in Issei's arms after having her Sacred Gear stolen, and thanking Issei for being her only friend, given that she was exiled by the Church years earlier. He is so infuriated that his Roaring Rampage of Revenge against Raynare, her murderer, is just as tragic.
- In the anime, Issei is begging God to help her as she dies.
- Kiba's past involves him and his companions subjected in a harsh environment to be able to wield a holy sword while believing in God. They all died except for him who was also succumbing to poison and only wished revenge.
- The scene of him reaching Balance Breaker state in episode 5 of NEW was done really well, the script, the melancholy music that is playing at the background, has put almost everyone in that area in tears. The ones who are not are Freed, Balba, Kokabiel and Xenovia, who is a stoic at that stage of the story.
- The Reveal that God Is Dead in Volume 3 causes everyone to suffer a Mass "Oh, Crap!" and a Heroic BSoD. Asia and Xenovia are especially anguished by this revelation since they believed in God all that time. For added irony, Xenovia becomes The Heretic and is exiled from the Church before she reconciles with Asia, who is also an exile.
- Koneko/Shirone's background: Her abusive master is killed by Kuroka, who then abandons her to die (or so she thinks). Thankfully, she was picked up by Sirzechs before being sentenced to death and she became Rias's servant.
- In a way, Kuroka had it worse. She left her sister to keep her from becoming a fallen, and when she finally had the confidence to take her back, Issei, thinking she would hurt Koneko, almost kills her and declares war on her. Ouch.
- Akeno lost her mother, Shuri Himejima, at the hands of her own clan and, overcome with despair, suffers a Heroic BSoD and blamed her father Baraqiel for his greatest failure, effectively leaving her an orphan. Having just crossed the Despair Event Horizon and knowing she can't go home again since the Himejimas are out to kill her, Akeno resigns herself to living out her days in exile when Rias takes her in.
- Later, when she and Baraqiel first reunite, Akeno snaps at him and says he isn't her father to his face. He looks like he's been struck by his own Holy Lightning. Fortunately, Issei and the Breast God help Akeno reconcile with her father.
- There's also the added layer that Akeno's predicament happened because Azazel sent Barakiel out on a mission only to be discovered by Shuri after he gets injured. Imagine seeing your subordinate's daughter disowning him for failing to save her mother from being murdered... and knowing that it was all your own fault.
- Sairaorg's past involves discrimination at the hands of his own family.
- As revealed in Volume 9, there are those who followed Cao Cao because he gave them a reason to live instead of being feared by their own peers because of their abnormal Sacred Gear powers. Issei even gets to think of Asia's life during the time she was a human with her Twilight Healing and that those who have Sacred Gears as a human didn't really have a good life.
- Issei's death in Volume 11. Hell, just Kiba's Wham Line "That day, we lost Issei-kun." can still have this effect.
- Not only Issei's death but the lead up to his death. Before he died he had just taken down Sairaorg and cemented himself as a hero in the devil world. His power had grew from a dirt-level devil to one that even a Satan could have trouble taking on. Not only that but he had just gotten promoted to mid class devil and judging from Azazel and Sirzechs' talk it won't be long before he becomes a high-class devil. Meaning his dream of starting his own harem wasn't a dream anymore. He also had heartwarming interactions with his friends such as calling Kiba his best friend and promising to marry Koneko in the future. To top it of he finally started dating Rias something which he had always wanted. When factoring in all his accomplishments, relationships and his future his death really is tragic especially since his death came out of nowhere. In short, the Diabolus ex Machina hits Issei, and hits hard.
- The prologue to volume 12 takes it up to eleven. It's set a few days after Issei's death. Ravel and Koneko are both trying desperately (and failing miserably) to contain their sadness, and end up crying in each others' arms. And they are the best off of the group. Kiba is verging into Stepford Smiler territory as he desperately fights to hold the group together. Akeno is in an Angst Coma, seeming more dead than alive. Asia wants to kill herself to follow Issei, only stopping because it isn't what he would want. And Rias essentially says that the world can burn for all she cares, if Issei isn't with her.
- In volume 12, the past possessors of Boosted Gear sacrifice their lives to stop Samael's curse while singing the Gropin' Dragon song. Normally it's funny, but somehow it's tear-jerking since they all sacrificed their lives and existences for Issei's will. Even Issei was silent about it.
- Ddraig almost manages to pull off one when he reveals that in order to maintain Issei's soul while his new body was being remade, he had to use his spiritual powers and that he's about to run out soon. Issei was almost about to cry at having his closest partner departing from him until Ophis tells Issei that Ddraig's just sleeping. With a loud snore coming from Ddraig.
- When Issei and Akeno visit the Grigori institute, Issei sees a wall full of paintings of people. When asked who they were, Azazel told him that it was a painting full of his old comrades who had died in the war and from other reasons. Considering Azazel's hundreds of years old, he must have seen a lot of deaths in his entire life.
- In volume 12, Kiba battles Georg of the Khaos Brigade. Losing badly and about to face his own death, Kiba and the demoralized Gremory Group hear Ise's voice encouraging them to look after his best pal. One of Issei's Evil Pieces transforms into Ascalon and allows Kiba to win the fight. Apparently even beyond the grave, Issei cares for his friends. A mixture of tear-jerker and heatwarming since at the time no one was sure that Issei was ever coming back.
- Valerie's last words to Gasper before she falls into a coma. To say Gasper was devastated that his best friend is going away from him would bring tears to anyone's eyes.
- Elmenhilde's predicament after the Vampire Cilvil War. She's utterly devastated that the male members of her family have turned on her, as well as the destruction of her homeland.
- The entire Star-Crossed Lovers story between Cleria Belial and Masaomi Yaegaki before The Alliance was formed in volume 18. Issei even ponders on it as it could have happened to him and any person in his harem.
- Volume 19 is abound of this, in particular how Vasco Strada addressed the DXD team after his defeat. To elaborate:
- He gives Asia letters from people she cured with her powers during the time she was still a nun. When she was exiled from the Church, Strada tried to reach her to give the letters with no avail, knowing full well that the people's honest confession and testament from the letters would make at least dampen her punishment and he wanted to help and put her under his protection.
- Kiba's reunion with the Holy Sword Experiment survivor, Tosca. Even Issei narrated that all the team can do is crying as they watch the heart-wrenching event unfolds and he analogues her for being a sheath for his best friend.Neither I nor my comrades who were lost for words, could do anything but shed tears for their reunion. ...Kiba, it’s truly great. What you’ve lived for until now, it exists! Because you’ve lived until now, you were able to see this girl again!When Kiba spoke — as if possessed by something, he seemed to have a gentle expression. ...To become a sheath to this guy that I’ve always been concerned aboutnote . Kiba had said that he was determined to protect her forever.
- He gives Azazel, and in extension Gasper, a fragment of the genuine Holy Grail, with later Valerie's subsequent awakening and reunion. Damn you Strada, if all men can follow your example, the world will become a better place in no time.
- Diehauser loses his will to fight to the point where, around the time of Rizevim's demise, asks Issei to cast judgment upon him and, after being slapped by Issei's mother, concedes defeat.
- According to the timeline of High School DXD EX, Instead of spending time with his harem and his kids, Issei is frequently called away to help with the problems of various mythologies. This results in him having little to no involvement in the lives of his own family and having his children be raised mostly by Vali and Kiba, and at least one of them resents him for it.
- Course the same kids refer to Issei's wives as keeping him on a tight leash, so it may be that just how often he is away from them is exaggerated for the sake of drawing attention to the one kid's resentment.
- The fact that Issei's kids refer to Azazel as the "Founding Governor" suggests that Azazel died sometime later, considering the events of Volume 21...
- Volume 21: In order to stop Trihexa for good, nearly all the faction leaders and their subordinates decided to seal themselves within Trihexa so that they can battle it to keep it from getting out. In particular, Vali is forced to watch as his surrogate father Azazel goes away, and Sona and Rias are left crying on the coast over the loss of their respective older siblings. Grayfia has it worse as she is the only member of Sirzechs' peerage to be left behind after being hypnotized.
- And before that, when Vali was trapped within the illusional world that Aži Dahāka created, it showed his innermost desire. To have a normal family. Even knowing it's an illusion, he can't help but be drawn into the warmth of having a family; he eats dinner with them, plays with his younger siblings and sleeps together with them. And even when he finally gathers the resolve to leave, he breaks down crying. And the icing on the heartbreak cake is, before he leaves, it's revealed that the father figure in this illusion that reflects his ideal family is Azazel, making the next bit even more painful when Azazel leaves with the other gods to seal Trihexa
- The fact that for readers, seeing the Tritagonist of the story leave for good is going to cause people to miss the snarky, awesome adult character.
- The first half of Volume 22 is a mix of this and Heartwarming, with the heroes, despite their losses, moving on with their lives and making plans for the future, albeit while being bitterly reminded of those losses from time to time:
- Issei is looking back at his life as he prepares to become a High Class Devil, thinking back to the events of the past 21 volumes. However, it ends with Azazel's last message to him, leading Issei to lament that Azazel isn't there to see his shining moment.
- Roygun Belphegor's current predicament in volume 23: she's exiled from her own clan for inadvertently helping the whole Rating Game scandal come into play. She has lost everyone who considered her a member of her household.
