I read the novel, and apparently women are stronger than men in such a way I think it's inverted between our world and the 1:5 parallel world. I can't really describe feats of strength, because it spoils things but keep an open mind on that detail.
I said this earlier, and you can take this as mental gymnastics on my part, but you could say this is an otome game reverse harem that got genderbent into an eroge harem... if that makes sense.
Take the latest chapter (Ch 19) for example, genderbend the basketball loli as a shota, who is being assertive towards the MC (who is also genderbent as an onee-san in this thought experiment). If I'm understanding otome games correctly, the shota would also escape the lil bro zone by acting very assertive and desperate by giving his beloved onee-chan a deep kiss, as the basketball loli did. Maybe the shota would try to do more based on what I know of romantacy and female-appealing kinks. If not, then I'm just yapping nonsense.
The very first girl that approached the MC and helped him register classes to me reads like an attractive guy helping a plain-jane girl register for her classes. The scenario where the MC's benefactor lets him live in a shanty apartment & work in a cabaret club kinda reads like a Yakuza 0 side story where Majima shelters a runaway girl until she gets back on her feet. The dedicated cabaret customer also sounds like a side story from Yakuza 0. Finally, and obscurely, the high school girl who needs tutoring - when genderbent - reads like an otaku who got lucky because their dad hired a hot tutor and a prelude to an h-doujin.