2- Takayama
3- Nagasawa
4- Hazuki
5-Gouda (by process of elimination if you assume Urashiyama is 7)
6- Best girl Fumika
7- Urashiyama (most likely)
8- Reika
9- Yuuki
10- Tezuka
J- Nagisa
Q- Sakumi
K- Karen
A- Souichi



Episode 1:
Urashiyama- collar was activated and he's being chased by the balls from the beginning. Death by explosion.
Hazuki- blood loss from Gouda's previous crossbow attack
Karin- Souichi and Sakumi hear gun fire, follow a trail of blood, and find Karin in a gun fight with Reika, but Souichi and Sakumi weren't close enough to get noticed by either.
Tezuka and Yuuki- they get into a gun fight. Yuuki died immediately upon Souichi's group arrival, Tezuka died soon after warning Souichi to not trust anybody or anything.
Best girl Fumika- Died from a landmine (set up by Nagasawa) once reaching the 5th floor. She pushed away Souichi and the others and took the blow. Died in Souichi's arms. Best girl death counter- 1.
Nagasawa- Hid from Souichi's group after ambushing them (killing best girl Fumika). Reika caught him by surprise and threw a grenade at him. Walked away like a bad ass.
Takayama- Reika surprise attacked Souichi's group at their barricade on the 6th floor. She used a remote control robot to attack Takayama and threw a gas bomb while they were distracted. Assume he died from the gas.
Reika and Gouda- Reika surprise attacked Gouda when she was about to kill Nagisa. Gouda plays dead and shoots Reika, who then shoots back. Both die soon after.
Nagisa- Should've been killed by Gouda and Reika during the same scene. Asked Souichi to end her suffering, he couldn't, so she put her hands on the gun and pulled the trigger herself. Was carried the Q PDA, so Souichi's condition was met when she killed herself while Souichi held the gun.
Activated collar- Balls would chase the person, tackle them, then explode.


Episode 2:
Sakumi- Died from 4 guns popping out of a wall after her collar was activated (assume Tezuka did it) right after the 6 hour fighting ban.
(Two others died, unknown who it is. Discovered by Hazuki from his software that told who was still alive. Dead are best girl Fumika and Yuuki. Revealed near the end by Gouda through implication when she says that only Karin, Souichi, and Reika are the only ones left alive after Tezuka's last attack)
Best girl Fumika- Already greatly injured when Karin found her. Karin finished her off. Best girl death counter- 2
Nagasawa- Shot by Karin soon after Souichi's group was about to reach the stairs to the fourth floor.
Urashiyama- Wanted to stay by Karin's side for his unlocking condition. Karin agreed and then shot him. He had the 2 and 7 PDAs on his person.
Nagisa- Tezuka was throwing grenades into the non-combat room. Nagisa threw her body on the third grenade (her reason for risking her life doesn't make sense at all since we barely even knew her at this point)
Hazuki and Tezuka- Threw Tezuka's second grenade from the non-combat room to outside, which caused his collar to activate. He went to confront Tezuka before the security guns would shoot him. They died together.
Takayama- got hit by the blast of Tezuka's fourth grenade (Tezuka held it as he was dying from the guns), got knocked out, then Gouda finished him off about 30 minutes after the ordeal.
Karin- Souichi and Reika had a plan to hold her down without getting into a gunfight. Souichi manages to tackle her, get shot in the neck (breaks the collar so he doesn't have to kill the owner of the Q PDA), but she somehow shoots herself during the struggle????????
Activated collar- Guns come out of the walls and shoot the person


Episode 3:
Urashiyama- There is a "chicken race" (extra game to get everybody to understand that the rules are real). The whole building is temporarily in non-combat mode. The last person to reach the second floor gets their collar activated. Urashiyama was last, so his collar activated. Activated collar- Spiked balls are shot out from the walls. One type has Liquid A oozing out of the spikes. The other type has Liquid B in it. If someone that has both Liquid A and B in their body, then they become a deadly poison.
Yuuki- stabbed by Tezuka and burned to death by her collar being activated. Burned to the point where only her sailor outfit was the only discerning characteristic that could be made out. Activated collar- flammable liquid is sprayed on to the person and they are lit on fire. A fire extinguisher would have a hard time taking it out.

3-A
Sakumi and Hazuki- Some stuff managed to happen that ended up with Hazuki killing Sakumi. Gouda then went in and shot Hazuki to death. Only told, not shown at all.
Reika- Nagasawa surprise attacked Souichi and crew while they were seeing if the gun (the first one they found so far) was real or not. Nagisa just got an order to kill Souichi, so she didn't notice it because of how shocked she was. Nagasawa tried to shoot at Souichi, but Reika blocked the shots and fired back at Nagasawa, injuring him. Reika dies from the bullet wounds and blood loss.
Nagasawa- Easily tracked by Tezuka and Takayama by following the trail of his blood. Death not shown, only inferred and referenced.
Takayama- Was about to make a peace treaty with Souichi's group after some negotiations, but guns suddenly came out of the walls (thanks to Gouda). Souichi's group had a place to hide, Takayama didn't and died. Tezuka didn't get shot because because.
Gouda- When Souichi and Nagisa met Gouda, 6 robots and 2 guns came from the ground, pointing at them. Right when Gouda was about to kill them, she was shot through a door... by Tezuka.
Tezuka- Was trying to kill Souichi as Souichi was trying to get to the control room to disable his collar. Tezuka thought Souichi was going to activate Tezuka's collar. Souichi managed to get Tezuka along with himself to roll down some stairs. Tezuka died from hitting his head during the fall. Tezuka had the Q PDA, so Souichi's unlocking conditions were met.
Best girl Fumika doesn't show up or is mentioned in the epilogue, so it's the same as her being dead for me. Best girl death counter- 3

3-B
Best girl Fumika- Shot by Gouda, but managed to get Reika to escape by using the traps against Gouda. Best girl death counter- 4
Gouda- Nagasawa and Tezuka managed to find Gouda soon after Best girl Fumika's death. Gouda lied and said that best girl Fumika attacked her first and it was self-defense, but Nagasawa already attacked Fumika once and knew that she would run away in a fight, so he know Gouda was lying. Nagasawa shot Gouda to death and probably would whether or not he heard the story.
Nagasawa- Tezuka knew Nagasawa was going to kill him for his unlocking conditions, so Tezuka did it before Nagasawa could.
Takayama- Tezuka got a call from Smith reminding him that he could get more prize money if other people died and that Souichi's group only had a PDA software that detects collars, so they wouldn't expect Tezuka to attack them. Takayama noticed Tezuka's surprise attack and told Souichi, Nagisa, and Karin to hide. Tezuka then shot Takayama.
Hazuki- assumed to be dead at some point. Not mentioned at all.
Sakumi- Tezuka admits to killing her (refers to her as the owner of the Q PDA though) after Nagisa shot Tezuka.
Nagisa- Surprise attacks Tezuka who was getting ready to surprise attack Souichi's group. Nagisa shot him several times to the point where he was incapacitated, but not dead, so she walked away like a bad ass. Tezuka still had enough strength to fire back and did several times. Nagisa still didn't do anything about that and kept walking... got hit pretty much in the heart by a bullet ricocheting of a wall...
Tezuka- Assume he died from blood lost from the bullet wounds.
Souichi- Died from his collar activating because he couldn't get it out. Use the door lock software to lock himself in a room so that Reika and Karin wouldn't get involved. Collar activation- mass gunfire. Assume it's just like how Sakumi died at the beginning of Episode 2.

Episode 4:

Nagasawa- Hit Souichi with a lead pipe before the initial non-combat time expired and his collar activated. Activated collar- harpoon like things fired at him and later electricuted him. He *was* with another group of people (Tezuka and Gouda), but they (most likely Gouda) purposefully choose not to tell him about the initial non-combat time to see what he would do.
Urashiyama- Stabbed and most likely got his collar to activate in the non-combat room by retaliating. Guns came out of the wall and shot at him. Attacked by the recovery squad (回収部隊) thing.
(Long ass fucking time later in the game) Gouda- Right at the start of the second extra game, Gouda goes to the rooftop of the building to tell the army guys that she wants to help them out. The leading army guy tells her that their orders was to kill everybody, but leave Yuuki unscathed. Killed Gouda right then and there.
Yes, these are the only people from the main cast that die in Episode 4.