Bokurano/Nightmare Fuel

It is a Kitoh manga, after all...

For entirely arbitrary reasons, a monster is making you and several others take turns to fight and destroy giant robots with your own giant robot. The giant robots act exactly like such devices would behave in real life, causing horrendous collateral damage, causing thousands to die for no reason each time a battle occurs. Once each fight is done, the pilot of the giant robot dies. No exceptions. So when your turn comes up, you will die. You can't just not fight, nor can you lose a battle, because your entire universe would be destroyed otherwise. Then it turns out that you're fighting other humans from parallel realities, who have been forced to do the same thing as you, so even if you win, their universe is completely annihilated. Remember: for no reason besides the giggles of the Eldritch Abomination. Oh, and your dashing heroes are between the ages of 8 and 14 and are all, more or less, terrified beyond belief. It Gets Worse. Mohiro Kitoh is such a kid-friendly mangaka, isn't it?
The 2nd credits sequence which depicts the kids in outer space, smiling, holding hands mostly in their pilot/death order. The music makes it even worse.
Watching every single star in a doomed universe disappear.
- All those empty chairs...
What Hatagami does to Chizu in the manga, that being setting her up to be gang raped by his friends.
- Yeah, and how he was videotaping them having sex the last few months, and showing it to them. That was fun too.
In the manga, during Anko's turn to fight one of the enemy's needles manages to pierce the cockpit, and it starts leaking a corrosive liquid above Machi's chair. Anko manages to push her out of the way, but she gets her legs burned off with the substance. While we don't get to see the clear effects of it, it remains horrifying enough when you consider that the liquid was strong enough to start melting Zearth's armor!

Back to Bokurano