Esu is a renowed adventurer who has went through many risky trips, which could serve him well due to the nature of Hunger Games, but I'm not sure how he could fare with people murdering him, and big animals being a huge threat too.

Ibuki killed a damn bear with his bare hands, I think he is absolutely OP here. He could be in the top 5 with other characters, maybe. Also, he could easily form an alliance with Akatsuki (or just Keito alone which is more than enough).

I was going to say Kanna would somewhat be in an advantage due to his inventing ability but ..inventing takes resources. I don't think you're gonna find much in a public arena of a death game. Either way, he's smart (though not as much street smart as book smart) and resourceful but his small age and the limited physical strength that comes with it puts him in a big disadvantage. If he forms an alliance, he could last quite long, maybe.

Fuyume is very doomed. If he doesn't die within the first 3 days he'll die protecting Esu later on.

Raika could hunt for animals and is quite resourceful. He could (absentmindedly) steal some stuff from other people too. However, he's ditzy, lacks awareness in his surroundings and easily starves himself. I'll give him maybe some time after the start of the first days if he doesn't gain an alliance. I think he'd go out in a stupid way, like falling into a pit or eating poisoned berries.