Contest winners, if I'm remembering correctly. They did something, somehow, in one of those gacha spinoffs that entered them into a raffle or ladder or whatever. Lucky winners got to see their character's name in the actual video game, rah-rah. Not as cool as knowing someone laid down their save data just to help you at the final stretch, but... It's neat?

Maybe they'll do the same thing for Missing Link and IV, assuming those games haven't been shadow-canceled at this point.