This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Mahou Sensei Negima!
When you see this, you'll WEEP brix.
After re reading the Kyoto Arc, there's quite a bit of Fridge Horror. Negi returns to the house to find almost all of his companions petrified, including Eishun. Bad, right? Remember what happened to Negi's village when he was four? And now all of that is happening again!?Imagine what that poor kid was going through at that point.
The episode focusing on ghost girl Sayo is tear-jerking, but the Gecko Ending is made of this. Asuna standing in front of her friends, unable to ask for their help to undo the Deal with the Devil that will kill her. Asuna's death. Negi absolutely falling apart when he finds the bell Asuna used to wear. After going back in time and changing history, Asuna once again standing in front of her friends, and this time breaking down and asking them to save her.
What happens during and directly after said death is saddening too. First, Asuna died just as she was gonna confess her love, then there is a funeral for her, and then she gets cremated.
Also, after Negi finds Asuna's remains, we get to see Yue's conflict with her growing feelings and her guilt, resulting in her absolutely blowing up at Nodoka, and Nodoka running away in tears. As if things couldn't get any worse.
Hell, the episode with Asuna's funeral is fairly depressing, seeing as how it opens, not with the usual peppy opening, but rather a montage of the other girls grieving. And to top it all off, we see Negi sitting on a branch of the World Tree practically sobbing his eyes out. Ouch...
Negi Springfield's last, and possibly only, meeting with his father Nagi as revealed to Asuna via a spell (and several others via Nodoka's artifact) in volume eight was heartbreaking. Not because of the destruction/petrification Negi's Doomed Hometown by an invading demonic horde or the impossibly powerful wizard doing a somewhat brutal Big Damn Heroes moment just in time to same the kid, but the fact that Negi only realized who the man was after he apologised for not being there and gave the kid his staff before starting to levitate off... whereupon we see the five year old (at most) kid running throught the snow before falling to his knees to scream "FATHER!!!" at the top of his lungs.
Of all the eavesdroppers (Asuna being too busy berating Negi for feeling the whole thing was his fault), the only ones not openly weeping were the Robot Girl (who looked as if she were trying to figure out how to), the Axe Crazy puppet ("The part where he broke the neck, that was cool!"), and the ancient vampire Nagi imprisoned within the grounds of Mahora Acadamy fifteen years ago. The last one of course pointedly turned away as she gruffly agreed to help Negi locate the man.
During the Festival arc in the manga, just before Negi goes to fight Chao, he asks Yue whether what he's doing is right, and says that if he joins Chao and helps reveal magic to the world thousands of people could be saved. Yue starts crying and tells him that he can't sacrifice his future for thousands of unknown people, saying "Then what about Nodoka? What will you do with your reply to Nodoka? Weren't you going to reply to her after she graduates? Are you going to join Chao-san and leave this school? What about Asuna-san or all our comrades or... me... Or what about everyone else from the class? Are you just going to leave us all behind?"
When Chisame is watching over the unconscious Negi while he takes the test to gain Dark Magic. At first she puts off stopping the test, because she doesn't want to ruin his dream, but she realises that if he ends up dying because of her indecision, she'd never be able to forgive herself.
The entire final fight of the Mahora tournament: Negi's opponent turns out to be a friend of Negi's father, Nagi, and has a special ability that allows him to take on Nagi's appearance and personality, acting exactly the same as Nagi. Essentially, this allows Negi to have his second conversation ever with his father. The entire match is a father/son bonding experience. What makes it even sadder is that the ability only lasts for ten minutes, and can only be done once, meaning that when the match ends, Negi's father disappears again.
Evangeline's "Can you at least pet my head?" moment directly after. What makes that scene even more powerful is that it is the only time in the entire series that Evangeline (openly) cries.
The end of the recent Rakan fight. After Negi has pulled out all the stops and finally managed to bring the invincible Rakan down, Rakan stands up again - but only to congratulate Negi on managing to damage him so much and inviting him to one last "Ala Rubra style" sparring match to end the fight. As they battle, Rakan muses that fighting Negi, since he's advanced so much, reminds him of fighting Nagi like he used to.
A combination Tear Jerker and Woobie moment comes in chapter 244, after Ako finds out that 'Nagi', the man she loved and Negi's older cousin, was in actuality Negi using magic pills to change his age. She breaks down in the bath, and though she's naked, it doesn't come off as fanservicey at all; rather, it's just heartrending, as she's even more vulnerable and unprotected than she already was.
We can't forget Akira walking on her, noticing she's shaken and trying to apologize for not telling Ako what she knew it all along. Then, Ako hugs her, and they both cry.
The episode with the ghost girl Sayo. It gives a much better impression of Sayo and Kazumi, especially when Kazumi decides not to take the picture after Sayo breaks down crying. Up until now she had been shown to be just as mercenary as her manga side.
Chapter 245. " Nagi-san, I love you. Or rather, I loved you."
Chapter 267: Zect dissolves right before Nagi's eyes literally moments after Lifemaker is defeated. Nagi breaks into a hysterical scream. And that was supposed to be their moment of triumph.
In Chapter 268, the various images of Queen Arika suffering due to the machinations of the Evil Senate. Can also fill viewers with RAGE at said senate. Of course, things do getbetter.
Chao's farewell scene Such a kind-hearted yet strong willed woobie, admitting her feelings to all her dear friends, without even thinking twice about going back to the hell she calls future. The fact that she didn't even shed a tear or ever complain or tell anymore how much she suffered makes this tropper feel really sad that she didn't succeed. Misaimed Fandom maybe?
Don't sweat it. Everyone (reader and character alike) wasn't sure if Chao was right or not. Besides, Negima's villains are made up mostly Anti Villains. And yeah. That WAS a Tear Jerker for me, too.
And then Chapter 298 shows us what she was trying to stop: a hundred-year war between Earth and Mars. Think about it: she grew up in a world where fighting, bloodshed, and death is all that anyone has ever known. You HAVE to pity her, especially since she willingly returned to that Hell after Negi defeated her.
Chapter 311. Just seeing the horrified look on the girls faces is enough to make you weep.
Chapter 312, end text. "For the sake of her comrades, for the sake of the world, Kaede is broken—!!" The last expression she takes on in the chapter is a small smile.
And it continues... Koutarou, Makie and Yue (after making a promise to hang out more) all fall.
At this point, there's a tear jerker every few chapters, to the point you want to shake Akamatsu and tell him to stop killing all these minor characters in depressingly heroic ways.
At first, Fate's consumption of ridiculous amounts of coffee seems like a mere joke, particularly given his extremely uncaffeinated personality. Then chapter 327 happens. While the first part of the chapter is a huge Crowning Moment of Heartwarming with Luna and her sister treating Fate in their house and Fate being grateful for how delicious her coffee tastes, the last pages have him return to their village, only to find the two of them lying on the ground as their village burns. Luna's sister recognizes him and tells him she's sorry she won't be able to make him coffee today, and then Secundum rewrites her with the Code of the Lifemaker. Secundum gets whathe deserves, but the chapter ends on a sad note with Fate remarking he won't be able to taste that delicious coffee ever again. And it only gets worse when one realizes that he's been drinking seven cups of coffee a day ever since then, in the hopes of finding just one that can bring him the same simple happiness that Luna's sister's coffee did. If that's not enough, it gets even worse when one realizes that, even with everything he went through, Fate may never have understood that it wasn't the coffee that mattered... but the person making it.
Chapter 334 tops it all, Negi and Co. finally defeated the seemingly invincibleLifemaker, only that said villain happened to be Nagi, AKA: the father that Negi was always striving to find, and the only words he tells his son in six years, right before disappearing again to who-knows-where? "Come and kill me, Negi. With that, everything will be over." Here's hoping Negi finds a way to free him from the Lifemaker's possession without killing him.
Considering things from a normal person's point of view: after all this crap... when you consider that she's been away from home for a long time, that she had at one point been a slave meant to work for several years, that she had seen friends die and come back to life, and that the stress she felt during the climax of the Magic World incident was such that she thought SHE was going to die, Natsumi is quite justified in crying at every normal, PRECIOUS meal she has had on Earth since returning to school. Only a few of us may know the overwhelming levels of relief she must feel about being home after experiencing these things firsthand.
Because of Magia Erebea, Negi is Immortal, much like Eva. While this wouldn't normally bother most people at first, Setsuna pointed out He wouldn't age and therefore could not live a normal life or father any children, meaning that the bloodline stays with him. This also meant that being in a relationship with any of the girls next to him was near impossible as well, since they would age and die, leaving him alone and miserable no matter what. There's a very good chance he will live a life much like Eva and suffer for it.
Chapter 343. While Negi is turned immortal, Asuna's fate is to sleep for a hundred years in the Gravekeeper's Palace, as a literal "cornerstone" for the plan to save the magical world. And they don't think her Kagurazaka personality will be able to hold up to it, and will fade away in the process.
Continuing from the above, Asuna's early graduation and goodbyes with Takahata and Ayaka.
Ayaka gives Asuna the time capsule they had buried earlier as a memento, considering by the time that Asuna awakens, Ayaka and the rest (except possibly Sayo, Eva, Chachamaru, Zazie and Negi) would probably no longer live in this world.
Chapter 351. Asuna's Goodbye. The tears on Konoka's and Negi's faces say it all.