Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: Kamen Rider Gaim
Kota's Heroic BSOD in episode 4, after Kamen Rider Zangetsu nearly kills him in the forest.
Kaito's reasons for wanting to be strong. His father once had a company, but it was bought out by the Yggdrasil company. Kinda sad if you think about it.
Imagine being in Mai's position when a true friend/crush flat out leaves you for a long period of time. Her frustration with Kota is rather understandable because of that.
The look on Micchy's face when he sees Zangetsu and recognizes the belt as the same one his brother was hiding in an earlier episode. It is almost heartbreaking to see Micchy's face and thoughts as it dawns on him just how little he really knows about his older brother. Not to mention the realization that it was Takatora who attacked Kota in Helheim Forest. It's so bad that Micchy kinda freezes up, and Kota has to pull him away.
#12: The aftermath of Ryoji losing to Kaito. His belt already destroyed, he also loses his Lock Seed and stage to Team Baron. His teammates desert him, and Hideyasu (who refused to help him out) coldly declares he’ll find himself “a new doormat”. Poor guy…
The people of Zawame City turning against the Beat Riders, due to the some sort of virus leaking off of the Inves, making people sick. It's really sad to see the people turn against the ones who have been bringing them joy for likely years.
Crosses a bit into Nightmare Fuel, but the fact they cheer for Bravo beating up a kid and possibly seriously injuring another.
#14: Kota's reaction to Hase's transformation into an Inves. From trying to reason with him and getting smacked aside, to faltering in delivering the final blow when he engaged him while he was terrorizing innocent civilians. The expression on his face when Sid executes Hase after he continually pleads for him not to really conveyed the sheer tragedy of the situation.
The first Inves from the first episode, turned out to be Yuya. Meaning... Kota unknowingly killed his missing friend.
To properly illustrate the above tearjerker, put this into perspective: For the most part, Kamen Rider, more importantly the Heisei Riders, focus on monsters using human guises. We're usually either introduced to the monster before their human identity or introduced to their human identity but have it revealed that they have a monster form all along or become one in the span of fifteen minutes from their debut. Here, we are introduced to Hase and he is no monster, whatsoever. In the time it takes from his debut to his death, we saw more and more of him. The tragedy comes with him, a long-term character who was part of the secondary cast, becoming the monster, not just the fact that he died. Very few Kamen Rider shows pull off something like what Gaim did.
#15: Micchy stopped Kota from finding out about Yuya's fate, not wanting his friend to fall into despair about the mess he kinda caused.
While mitigated by the fact that they ditched him in the first place, seeing the Raid Wild Riders wondering about the whereabouts of the (unbeknownst to them) deceased Hase is really tragic and dramatic.
#16: Seeing Mai on the verge of tears. What makes this so sad is that it's RARE to see Mai in this sort of position of helplessness and sadness.
Whatever it was that Takatora showed Micchy must be one. The sight of it brought Micchy to his knees and utterly broke him enough for him to change sides. Hell, even seeing how Micchy reacts to the sight is definitely one. He is traumatized.
#18: Things haven't gotten better for our heroes. After Kota beat some Inves, he went over to make sure the people were okay, when they fled from him like he was one of them.
#19: You can just feel the tears about to come from Mai's face when Kota tells her, he won't stay with Team Gaim.
#20: All of the Inves were human/animals at one point. All of them.
Kota's face as he looked at the ruins of the city within Helheim. Never had we seen his resolve broke so fast and hard, which only gets worse when Takatora tells Kota that all of the Inves were once humans. It was Ryoji all over again...
The information we're fed makes Micchy's actions concerning trying to make Kouta and Mai happy the past few episodes, as well as him saying that he'll betray anyone to achieve joy, all the more poignant. Wouldn't it be what you would do if you were one of the select few who were told the world will end in ten years?
While it's been very obvious before, this is the episode where it becomes clear that Takatora is a pawn to the other Energy Riders, who are all Ax Crazy Social Darwinists. It's sad, seeing Takatora care for them so much and actually trying to do the right thing while his "friends" use him so Helheim can kill the weak.