Tear Jerker / Cardfight!! Vanguard

• Misaki's backstory being revealed via flashbacks of her parents' deaths that give her a breakdown until she has to stop what triggers them. Which is playing Vanguard.
• Episode 49, specifically Ren and Kai's backstory. Watching Ren transform from an Adorkable kid into his current persona is heartbreaking.
• In episode 50, Aichi's anguished rant at Kai. Effects of PSYQualia aside, he was probably keeping most of what he said bottled up inside for pretty much the entire series...
• Aichi in Season 2. It's a Tear Jerker in Hindsight: he's lost the clan that meant everything to him, which everyone doesn't remember, but him. Think about it: the Royal Paladins were the reason why Aichi was able to develop into the person he is today, the first clan he got to personally KNOW through PSYQualia, and Blaster Blade was the card that inspired him to start playing the game in the first place.
• Episode 102 has quite the Tear Jerker: Aichi arrives at Leon and Kai's fight as it finishes and rushes to Kai's side, whose initially unresponsive. Kai apologizes for having not been there to fight for the sealed clans by Aichi's side, while the whole time, he sits there in tears from just listening. When Kai, Ren and Asaka begin to glow from their dismissal from Cray, Aichi clings to Kai, pleading for him not to disappear and encouraged to fight on before they disappear, which is followed by Aichi giving a Skyward Scream Say My Name and breaking down in tears completely before Leon. Even Charlene and Jillian feel for him.
• Kai's feelings of inadequacy in Link Joker. He's had them for quite some time, at least since Episode 103, some months before the third season. They slowly begin to eat away at him and it becomes increasingly difficult for him to hide his real feelings, almost opening up to Miwa, though his words are mostly lost. Their worsening correlates with Kai's declining state and culminates with Kai's conversion to Void's side, killing off part of himself while in an unstable state of mind. It gets worse as Kai's loneliness is something that the season is going to cover, leading to his Start of Darkness and in an interview, Takuya Sato reported how difficult he found it to record the episode.
• Izaki Yuta in episode 121. The flashback showed he was a beginner like Aichi, making mistakes during their first shop tournament because they are too nervous. It was a bit sad on Izaki, knowing he had been watching Aichi evolved way too far from him while nothing seem changed for him. Audience opinions of underestimating him and obvious outcome aside, Yuta wanted to win so bad against Aichi that he ended up shedding tears after he loses. But turn out as Heartwarming because the audience, change of heart applaud him and Aichi, his opponent shake hands out of friendship.
  • Count as Heartwarming for the part his friends help to train him because Kai of all people along with Miwa and Morikawa agreed to do so and give advice to him.
  • Another case similar to Kamui after he got Reversed by Kourin. Aichi was literally weaker at the beginning in vanguard compare to him. Even when they were on the same team, Aichi strides way higher and become out of his league as the series progresses. Something Kai also felt frustrated about.
• Yuri's fight with Reversed Koutei in Episode 136. She's fighting an opponent she cares for a lot and who she helped rise from being basically an inept beginner to a national champion, and who is now Brainwashed and Crazy to the point of being the exact opposite of his normal self. By the end, she's screaming his name, trying to desperately bring him back to his senses, only to be cruelly defeated by Reverse Daiyusha and reduced to a mindless Reverse fighter. Made even worse if you knew Episode 137's title before, and thus know that she's in a Hopeless Boss Fight.
• Gillian and Charlene getting reversed in Episode 137. The entire episode was planned brilliantly to show the audience more in depth about the relationship of Leon and the Twins, and just why the Twins are so loyal to Leon. Their interactions just melted the hearts of the audience only for Reversed Kenji and the Reversed Team SIT to thrash the party. Not only the three of them were separated to fight individually, but Leon was helpless (As he was fighting Kenji) as he sees the Twins get defeated and reversed. Gillian and Charlene were clinging to Leon's memento (a boat origami made by leaves) while trying to reach out to Leon while saying his name (In tears no less, because they had failed him) as they get engulf by the ebony flames...This is definitely one of the most heart wrenching episodes in Vanguard anime history ever.
• Aichi's loss against Reversed Kai. While Kai iterates what drove him over the edge, Aichi is on his knees, clutching his chest and screaming while trying to fight off the Reverse. It doesn't get any better after he's saved from converting by Takuto, who says that Aichi is virtually on the brink of death and that if he fights, the Reverse still in him that he's holding back will take over. Even after hearing that, Aichi is still adamant to go after Kai, even though he can't even stand and has to be forced into passing out just to stop him from putting his life on the line.
  • Makes it even sadder when you recall that Aichi loved Vanguard so much that he spent the first half of the arc just to establish a club in his school. And now, he can't cardfight at all (Reversed opponent or not). The game that changed him to who he is and got him the friends he has is KILLING him.
• By the penultimate episode of Link Joker-hen, Kai has completely lost the plot; he intends to disappear out of Aichi's life and his speech is that of someone very suicidal, blaming himself for all the trouble Aichi has run into and believing everyone better off without him. That alone is heart-wrenching, but what tips it over the edge is how Aichi copes with hearing the person he admired so deep in self-loathing and begs for him to see that he's the reason Aichi is who he is. Overlaps with Nightmare Fuel and Heartwarming Moments.
• Ultra Rare's past, particularly its effect on Kourin. As Takuto houses their memories, stripping them of their past prior to being recruited by him, it's used as an argument against Aichi's fighting, as when Takuto disappears, so will the girls' past memories, and Kourin's since have focused heavily on Aichi, which was her motivation for fighting while Reversed.
• An example that is more of a Tear Jerker in hindsight; before leaving to fight the final battle with reversed Kai and Takuto to defeat Link Joker (while on the brink of being reversed) , Misaki makes Aichi promise her that he'll return, alive. Queue season 4, where Aichi has disappeared, and no-one apart from Kai remembers him, not even Misaki and her perfect memory. Her voice is just so heartbreaking when Kai makes her remember.
• Episode 183. Despite the massive flak given by the fanbase on the poor writing of the episode and skipping most of the battle (Which was considered the charm of the Vanguard anime), one can't help but to empty their tear glands when Misaki received the Memory Judgment, which caused her to forget Aichi, again. Cue to her standing in Card Capital and staring at Kourin's ribbon, still strapped to her hand, and finally broke down in tears over a reason she can't even remember. The plot has never shown mercy to Misaki, but it reaches its peak now.
• Episode 184 - 185, Gaillaird's past was revealed. He was an orphan who could not make any friends. However, Vanguard change his life when he received a gold paladin card from a member of the same orphanage. As the story progresses, Gaillaird make more friends and later decided to look after the orphans that are to come while instilling the excitement of Vanguards to them. Sadly, Link Joker invasion change everything. The orphanage regardless of age were reversed and they reverse the young ones as well. Gaillaird was too late and had to fight them without reserve to free them. The situation was a complete despair, as fighting those young kids he cared is like tearing himself apart. Gaillaird got exhausted and suffer from all that. He thought he would rather be reversed.
  • Even when Link Joker invasion ended, one of the kids named Nicola, was overwhelmed by the terror at that time. Gaillaird was sad enough from what happened during the invasion but even more when his attempts to persuade the kid into playing Vanguard again and his feelings fail.
• Episode 193. Naoki vs Kourin. It is revealed that when Kourin loses her memories she began wandering in the public with no aim or destimation.
• Episode 195, because Aichi was freed and Link Joker's will was weakened greatly, Aichi and Kourin got to talk one last time in astray form. Kourin started to disappear both physical and memories while telling Aichi that Photon card was her remaining memories about Aichi and the others.
  • If you actually focused on the second op and end. The end was even sadder. Kourin was left alone while only Aichi return to his friends.