Is this a reference to SaGa 2? If we remove "chirei" (地霊) from the commentary we get 秘宝伝説, and Googling that gives us this game

EDIT - Yes, Satori's third eye is shaped like Teacher (Saga 2).

Okay, these are specifically based on the artwork for the Japan-only DS remake of SaGa 2.

It appears both Satori and Koishi's Third Eyes are different Teacher designs available in the game? I'm guessing the two themselves are one of the four possible Female Humans and Female Espers, respectively? And Kisume is one of the four Mecha/Robots? Unfortunately the only resource I could find that has any information about this version of the game is the Wikia for SaGa, which only has partial uploads of the character portraits, and doesn't label some of them with what the four options for each race are, so I can't tell. The only other character whose art was uploaded that I could identify was Parsee, who is cosplaying as Kai.

If I were to guess based on the original Game Boy game's art, then Yuugi would be Hana/Otama and Orin would be Lynn, but without seeing the DS art I wouldn't know for sure (and that still leaves the question of who everyone else is).