- The entire premise. 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 for no reason besides the amusement 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.
- 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.
- And when it's her turn to pilot Zearth, she puts off the fight to go snipe her rapists with lasers. Including one who she can see is carrying a little girl who's probably his daughter. And since it's doubtful that Zearth's giant lasers have the kind of precision to kill only him, that means she deliberately murdered a small child in cold blood.
- 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!
- The thought of Chizu's unborn child being in the contract is just too horrible. When you're in the contract, there's a constant chance that your turn will come, even if you're in no physical condition to fight, in which case your Universe's best bet is to have another pilot kill you and take over your turn. Think about it. There was a constant chance that Chizu's unborn child would be chosen to pilot Zearth!
- Even at the end of the story the battles are still being fought by others in altenate realities and billions are still dying with no sign of it stopping.
- The final battle. The pilot of the enemy robot tricks Ushiro into opening his cockpit without killing him, allowing to teleport away. Now potentially anywhere in the away team's world, and with only 48 hours to find and kill him, Ushiro ends up having to win the fight by personally killing every single person in this alternate world until he finds him. And what's even worse is that he figures out pretty quickly that this is exactly what the enemy pilot wanted.
Nightmare Fuel / Bokurano
It is a Kitoh manga, after all...