A Certain Scientific Railgun/Tear Jerker

Episode 5, watching a little Uiharu crying for help as she watches her friend Kuroko getting beat up by the bank robber, you can't help but to cry yourself and wanting to hug Uiharu to calm her.
Uiharu telling Saten not give up as she will wake her and their friends before they succumb to the side effects of Level Upper. Saten is grateful of what she said before she falls into a coma.
Uiharu and Saten's reunion after being cured from Level Upper and Saten realizing there are some things more important than powers; her best friend. Awww...
Misaka 9982's last moments before her death is just, so, heartbreaking...she's lost a leg, and is crawling towards the Gekota pin Mikoto gave her. She picks it up and smiles...and then Accelerator drops a train on her.
- Oh, and Mikoto saw this entire thing. The next chapter starts with a brief flashback to her speaking with Kuroko about the possibility of clones.

Kuroko: What would you do if a clone of yours appeared before you?
Mikoto: Ah, that would freak me out. I think I would wish it would just disappear.
(present: Mikoto goes ballistic on Accelerator)

Watching Misaka's Doomed by Canon attempts to end the level 6 shift program, and her slowly breaking until she hits the Despair Event Horizon.
What happened to Kiyama's students and what she had to suffered to saved them makes you want to support her.
- But it gets better later, after several setbacks, Kiyama is able cure her students. The moment she shed her tears, you can't help but cry too.