Hahaha that was pretty funny at the end, "And in response another part of my body gave an involuntary thumbs up" ... Aside from that though this MC is kind of annoying to be honest. I guess it is somewhat more realistic that he isn't all super hero or super villain but ... Well, I heard there is actually pretty good character development so will just trudge along.
The way how new entrants spawn into their little mysterious room looks especially nasty when they happen to be naked. I have to agree with Kurono about how it's weirdly arousing as well despite how grotesque it looks.
Poor naive Masaru got disillusioned by how his awesome childhood friend turned out.