Why did Izumi first leave? Plot hole or Theories

Random Question: Why did Izumi first leave?

(Spoilers I guess)

I got in a debate with my friend the other day trying to brain storm logical reasons why Izumi would ever leave the Gantz game in the first place given his personality.

Izumi's been long dead so unless that far fetched 'everyone comes back' theory is true his significance to the plot is probably done, but somethings still bugging me.

Izumi used to be in the game pre-Kurono's time, but got 100 points one day and decided to leave.

Does anyone else find this extremely out of character for him?

Izumi seems to love killing. Before being slaughter by the vampires he picked to have a better weapon next round. He's extremely aggressive and Gantz seems like a 'wonderful' outlet for him to express his true nature.

My friend came up with two explanations and I only manged to revoke one.

Idea #A

Its yet another character motivation plot hole from Oku!

(I'd like to give him more credit then that.*sweatdrop*)


Idea #B (That I revoked but if you think you can put it back into play with evidence feel free)

Izumi had a different personality before setting himself free.

My argument against this uses two factors.

1. His personality before getting into Gantz the second time was brutal and had the capacity to kill even without his memories of the game. He wanted back in and seeked it out.

2. Nishi seems to like Izumi. He's got a happy/surprised look on his face upon noticing him in the room and before the vampire fight on the train had a smile on his face that vanished the moment Izumi said he couldn't remember anything about him.

(I doubt he'd take orders but,)
He also suggests to the group Izumi be the group leader and that he was a leader to the group pre-Kurono time.
(another wait then why'd he quit u.u moment)

All this persuades me to believe that Izumi before leaving was a friend or at least someone he liked or respected by Nishi.

Nishi defiantly doesn't care for bleeding kind heart's like Kato or appreciate people who do not see the world like him.

This inclines me to believe Izumi must have behaved in a similar way he did in the manga even before Kurono's time.

So why would he ever decided to leave it?

I'd love theories from you guys!

It wouldn't be as fun if it was just a character motivation hole. >.<

Well, according to Gantz Minus, Nishi and Izumi's first hunt was the same for each. I also think that Nishi's personality changed to his more independant one from a hunt where the hunters did become rivals, maybe they ran out of time in a hunt and when Gantz said they each had to get a certain amount of points, there wasnt enough aliens to go round.

Why would Izumi want to quit being the leader? Well Kurono's had a few 10 minute retirement thoughts, especially after the Tae-hunt happened. It wouldnt be weird to think Izumi thought about this, but once he was free, he realised what the hunts meant to him and he realised he messed up. His dialogue pretty much confirmed it.

Maybe he went free because thats what Ooki, from Gantz Minus did with his 100 points. Im not sure as I havent read the novel, but I think at that time, the team needed a leader with very few people remaining at that point and Izumi stood up to the plate.

He moved to a different city, so he had to exit the game. How would he explain to his parents every time he vanished and ended up in Tokyo, needing money for a plane ticket home?

Once he transferred back to Tokyo, things changed. He ends up at Kurono's school, after first tracking him down on Nishi's website, that perhaps the reason he transferred even.

Only the first Gantz Minus was translated to my knowledge. If ever someone decides to do the rest, please post about it everywhere.

Isn't there software where someone could automatically read it into something that could be copied and pasted in Google translate, and at least make it partially readable? I don't think they'll be licensing it in America in the near future.

There is a novel coming up where they explain why he left.

(I havent read Gantz minus, so i dont know a lot of things about it, sorry. If anyone has a link with any kidn of translation...)
I remember Izumi had a mini-sphere, which Kurono didnt get when he left gantz. I think Izumi did something special before leaving, in order to get that sphere.

I think he just found it. Gantz sent that to him, telling him what to do. Kurono wouldn't be willing to murder innocent people like that, so Izumi was the one Gantz contacted.

^ Yeah, he says he found it the other day, he didnt have it the whole time. I believe he was sent it when Kurono messed up the Chibi hunt and Gantz lost his patience with him (His welcome screen to the newbs in the Dino hunt called the recent hunters weak too). Ooki could have been sent a mini-ball too feasibly.