- Nadeshiko's death in Megamax and Gentaro's subsequent heartbreak as he sees the girl of his dreams die in front of him and after he accepted that he liked her even if she was space slime. This is one of the only times he goes into Heroic BSoD.
- And then much later, it's revealed he has the Super-Rocket switch and says "Nadeshiko..."
- Gentaro's death in #31, made even worse because Ryusei's identity as Kamen Rider Meteor is revealed and Kengo crying out "KISARAGI!" in vain. And it gets worse in #32 when Kengo trying to use the Medical Switch has no affect in bringing him back to life.
- Made even worse due to the fact that Gentaro wasn't mad at all. He was actually happy that he was finally able to get Ryusei to open up and be able to help him out even if it meant he was going to have to die in his place. GOD DAMN YOU.
- During the scene where Kengo checks up on Gentaro, you see Shun in the Power Dizer with Berserker Tears. He was so enraged on seeing Gentaro, who helped him see the light, dead by a person that Shun saw was himself in the past. No wonder Shun wanted to kill him.
- The worst part about the above? All of it was rendered moot as, after getting Aeries to heal Jiro and get him to turn the switch off, he noticed Ryusei's sadness and, after finding out that he became a traitor to try and save his life, relapsed, his body fighting the healing process after what he heard about the burden his friend put on him. This means that Ryusei gave up everything to save his friend, only for the actions he took to put him back in that state. Jiro is still in the same position he's in, he left his school under the Aeries Zodiart's tyranical control, and he betrayed Tachibana (losing him the ability to become Meteor) and the Kamen Rider Club, himself included, as he ruined his chance of befriending him both by... well, killing him off but also because, despite his denials, he really wanted to become friends with him. With all this, when he goes back to rescue the Kamen Rider Club, he fully expects to die holding off Aeries and his Dustards, as he has nothing else to live for. Granted, Gentaro came back and saved Ryusei but still, it's quite a brutal moment.
- The end of #38 has Erin forgive Yuki for causing so much grief after learning what happened in the previous episode but can't accept Gentaro's sign of friendship since they're a Kamen Rider and Zodiarts. To this, Gentaro defeats her in battle and then Virgo whisks her away to get her memory wiped. She's last seen where she was first seen in #37, but she asks who Gentaro and Yuki are.
- #41 has The Kamen Rider Club splitting up thanks to Virgo. Ohsugi departs but tells them about one regulation: Don't die. They're very simple words, but it proves that Ohsugi sensei is also a member of the club, and it makes one's heart break.
- #43 and #44 has everything involving Yuuki, but especially when Dark Yuuki tricks the Kamen Rider Club into thinking Yuuki is the impostor, and she's lost so many memories she can't even remember their names to be able to tell them she's the real one!
- #47, Kengo's going to leave for space and meet up with the Presenters and Gentaro and Yuki cry because this'll be the last time they see him. And then, the Rabbit Hutch gets destroyed, the KRC gets beaten and bruised—including Ohsugi-sensei—and then just as Kengo is about to become Kamen Rider Fourze, Gamou gives him a Rider Kick and crushes the Core Switch killing Kengo.
- More importantly, When Kengo realized who he was, he lost all of his emotions. He reverted to an empty emotionless doll who speaks in Creepy Monotone and states that friendship was "processed data", Gentaro was stated as "illogical existence" and that he called himself nothing more than data. Just seeing Kengo losing all of that Character Development is heart-wrenching...and then it's revealed to be an act because he believe that's how he's supposed to talk and he doesn't want to leave his friends.]
- "You and I are friends...We may be apart but it's not so bad! Go on to see the Presenters! You're representing everybody on Earth! So even if you're in the farthest parts of space...We'll come...to see you again...so wait for us...(cue Kengo hugging a sobbing Yuki Jojima)
- The promo for #48 shows that it will keep a Tear Jerker feeling. To see a series that was most lighthearted to end like this is kind of strange.
- It does. First, the Rabbit Hutch explodes. To witness the destruction of the place where the Kamen Rider Club developed as a group... well, to someone who followed the series from beginning to end, it's like watching a second home being destroyed. Then we hear Kengo's letter to the group, and... cue the waterworks.
- Reality Subtext makes it even sadder: In a post-series blog, it was revealed that the letter scene was actually the last one filmed, and the cast and crew had become very close over the course of filming (with head director Koichi Sakamoto even saying that he'd come to view the main cast like they were his own children). So the tears were 100% real — and only exacerbated by the fact that Ryuki Takahashi (Kengo's actor) couldn't be on set for that scene. Fumika Shimizu (Yuki's actress) even admitted that she considered deliberately messing up her line reads, just because she didn't want it to end.
- A Meta-Moment years later, but just the fact that due to several factors including Ryuki Takahashi's deteriorating health forcing him to retire and Fumika Shimizu joining a goddamn cult, we'll never get a reunion of the KRC.
- Heisei Generations FINAL makes it even more painful: Gentaro, JK and Ohsugi-sensei all return, and Kengo and Yuki get name-dropped, but all the stills from Fourze that appear during the end credits are deliberately cropped so Shimizu isn't visible in any of them. On the other hand, it's obvious that Gentaro is still friends with Yukinote , so even if the actress won't be returning at least Toei isn't taking it out on the character.
Tear Jerker / Kamen Rider Fourze