- Mimi's behavior in chapter 37 is extremely jarring, to say the least. Leaving aside the advice she was giving Yolei, the caustic way she treated the waiter and then Joe is horrible when you consider she had the Crest of Kindness before.
- Yolei's steadily worsening behavior, alienating her friends in the process, culminating in her publicly insulting Sora about her relationship issues along with her parental issues in chapter 42. Sora had been nothing short of supportive until then and she threw it all back in her face. And then, when it came out she wanted Ken, Mimi (who had her own issues with him because of Palmon's enslavement) left her as well. When Poromon asked how many friends she had left, she didn't bother giving him an answer.
- The ending of chapter 49: just as the Digidestined managed to reach the home stretch, Cody decides to challenge Ken to a duel to the death, only for Oikawa to suddenly appear and bang Ken dies with his own pseudo-gunshot. By the time they realized it, everyone became heartbroken about this revelation. Even Cody, who hated him with passion, breaks down at the fact that he will never be able to apologize to Ken ever again and realizes the error of his way and feels remorseful for how he treated him in his narrow-minded view.
- This leads into another set of touchingly tragic scenes in Chapter 50, as Matt and Jun have to explain human mortality to Demiveemon and Upamon- who initially assumed that humans, like Digimon, were reconfigured- while Joe has to help Mimi through her own grief-induced breakdown at this first direct loss of one of the Digidestined.
- Near the end of chapter 64, the team find out that they've all been Oikawa's pawns all along, which is then followed by him brainwashing and kidnapping the new kids' partners. Everyone has a massive Heroic BSoD over this... until Davis snaps them out of it by refusing to give up.
- Chapter 68: Oikawa forcibly merges Mummymon and Arukenimon, spending the entire time insulting them as failures and then turning them to an abomination despite pleas for him to stop and the fact that they were literally made from his DNA and the closest thing he had to children. The group as a whole can only pity them and then have to essentially banish what they've become to the void between worlds to get rid of it because of him.
Tear Jerker / Digimon Adventure 02: The Story We Never Told