Surely the author knew what they were doing with this. I mean Saitou is just too stupid to not be intentional. He acts all high every chapter, only to get his ass handed to him by the other characters with actual powers. It feels so bad at times it has to be deliberate, almost a mockery of the harem genre by having such an obviously stupid kid gain a harem. Which, I didn't even think it was, given the lack of harem tag, but it is, no doubt that invincible and mind-reading girl were each into him. Plus that yandere girl at the end.
Surprisingly the comedy was actually funny, its refreshing to see that amidst the same old. I assume most harem fans didn't like this, hence the low volume count. Nonetheless the series did well with its limited time, especially since arcs in this story usually last several chapters. I do wish this continued so I could see Saitou gain time travel powers and actually mature as a character. Still, the ending is rushed with the ax and all.
7/10.