This episode started off a bit unjustly for Shintaro: he wakes up in a random bedroom (that turns out to be Marry’s) and Ene makes him strip before she’ll tell him anything, and that’s how the other Mekakushi Dan members find him: in his underwear, on Marry’s bed, staring at his phone. For that, he’s tied up and ridiculed. Where is the King’s Justice?
At any rate, Shintaro is part of something bigger now, whether he’d like to be or not; it’s either become a member or become a hostage, as he knows too much to be neither. It’s obviously a lot to take in for a shut-in meeting five new people all at once. This is also interestingly the first time we’re seeing Shintaro and Momo interacting as bro and sis, and it’s…adequate.
The entire episode was similarly adequate, filled mostly with sitting or walking around not doing much of anything, but couple new connections were made. When Shintaro went off on his own he bumps into a very memory-challenged Konoha, who spots Hibiya and Hiyori (who ISN’T dead!) getting kidnapped and acts instinctively with some pretty awesome superpowers.
We also learn that the founding commander of the Mekaushi Dan was Ayano—something Shintaro probably didn’t know. Between Shintaro’s (and Hibiya’s) “dreams” that involve her and the strange fairy-tail like stories about a monster girl that end each episode, there are still many mysteries left to solve.