Fridge Horror: In the mid episodes, Safu's grandmother dies. Safu receives her remaining personal items - her grandmother's glasses and one knitting needle. The second needle is what Shion grabs onto when climbing the mountain of dead bodies, which means Safu's grandmother was simply dumped off with the rest of the corpses.
Let's not forget the fate of the slumdwellers who are dumped into the room with the dead bodies - if any of them survived the fall like Nezumi and Sion, they are trapped down there with no food or water, surrounded by corpses. Logically, that would lead to rather desperate circumstances.
Ho Yay: You CANNOT find a discussion on this series without finding a bunch of people talking about how this looks like it's going to be Boys Love. Now has its own page.
Moral Event Horizon: Episode 10, the guard Shion killed crossed it when he murdered one of his own men for failing to capture Nezumi and for getting taken as a hostage instead. Then was planning to kill Nezumi next.
Narm: Shion's mom screaming out his name at the end of episode 8 once she read his pretty-much-a-suicide note. It was supposed to be tragic, but she's the one who told him to save Safu, you would think she's expected that to be pretty much a suicidal mission.
Nightmare Fuel : Along with the other people, Shion and Nezumi were dumped like garbage into a pit in Episode 9. Shion vomits when he sees the literal MOUNTAINS of dead bodies.
Tear Jerker: Shion calling out in vain to his mother as the police car he's being held in passes by her.
Throughout episode 10, Shion begins to shed his Pollyanna status and become more hard-hearted, no longer crumbling at the deaths around him. Nezumi displays a veritable laundry list of heartbreaking expressions as he realizes this...ending in a full fledged breakdown when Shion coldly shoots a guard.
Episode 11. Just...just...episode 11.
The Woobie: Poor Shion was stripped of his status as an elite when he was a kid, just for helping another kid. When it looked like he'd pulled his life back together and was living happily, he wound up simply being in the wrong place at the wrong time and torn away from the people he loves.