In total, there were more than twenty people who signed up to explore Dungeon Spire, and that's not counting the five people in the top ten who signed up, specifically Plunder, Life and Death Angel, Technomarine, and Splatoon. Quite surprisingly, Satoshi's mom didn't sign up for the Dungeon for reasons unknown and she didn't wish to disclose them. Everyone was a bit concerned as to why she didn't join but no one dared ask her.
Apparently, Tatsuki (Plunder) specifically asked his wife to not join the party, telling her that it would be dangerous. 'If anything goes haywire, then at least Satoshi won't be left alone.' He said, to which Ayumu shook her head in rejection.
"At least I'd be there to protect you," Ayumu reasoned out.
"As if I need protecting." Tatsuki smiled. "We have to do this, remember the Boosting Incident? I don't want that to happen again. And if we can't help it, then at least we should do what we can, right?"
sniffle~ (ಥ﹏ಥ)