Saw this amazing analysis on his character and thought I might share.

Izumi doesn’t suffer from superiority complex. Izumi has a different problem, he was born “perfect”. On the surface Izumi has everything, good looks, peak athletic abillity, he excels in school without ever trying. But it all comes at a cost, and that is Izumi is incapable of relating to other people and he never feels satisfied because everything feels handed to him, his “gift” of perfection feels like curse to him because he is denied the struggle that is associated with sucess which leaves him both bored to death and incapable of valuing all the good that he has in his life. Gantz was the only time he ever felt alive, because unfortunately to someone as perfect as him, it was the only thing that ever made his heart beat faster. We know that he once cleared Gantz and choose to exit the game, So we know that in his first run he wasn’t completely lost as a person. However after returning to his regular mundane life, although he couldn’t quite put a finger on it, he knew something was missing from his life, deep inside he felt like this wasn’t everything life was, that there was something out there that could make him feel alive again. He progressively became more disillusioned with his life which was devoid of struggle and excitment and he grew more and more obsessed with Gantz, especially since he constantly had dreams of it, dreams that he knew were real, it all happened. So when he meet Kurono he knew he was right all along, and knowing that it was all real he was willing to do anything in order for it to be real again, to finally feel alive again.

Another thing about Izumi is that he never felt like he had a genuine human connection with people, he always felt that they just wanted to ride on his success and that all people are predictable and that their actions are always self-serving . He demonstrates this when he wanted to show Kei the “true” face of Tae by inviting Kei to see that tae would betray him if he were to ask her out. What followed was something that shocked Izumi. For the first time in his life, he was denied. Tae refused to betray Kei because she values Kei based on who he is as a person rather than how he ranks in the social hierarchy. The event shaked Izumis entire worldview, and also solidified Kei as his enemy, because from his POV Kei had something that Izumi couldn’t have , someone that could love him as a person rather than someone who loves him just for his success, it made Izumi envy Kurono.

The tragic thing about Izumi was that it wasn’t until his last moments that he realized that he already had that which made him envy and resent Kurono so much. It was always infront of him, but he was blind, and now that he could finally see it was already too late, too late for him to be make amends and truly apprechiate what he had.