there's a lack of character progression that is getting more obvious over time
the girls accept that MC is the leader, and might have a single emotional event with him
but then slip into a completely static FWB relationship
for example, there was one scene where Yuki called MC 'Master,' and then this was never mentioned again
Scarlet and Sarah are favorites (probably) but I still don't know if they want to be girlfriends, wives, part of harem? There's almost no story there beyond new sex acts.
Leah, Nadia, Hazel, Sonya, Daisy, Jeanne, etc are not as interesting, but I'd still like to clearly know if they are serious about MC or just playing along with the BDSM for giggles. (Which only really makes sense for Hazel, who called herself a wingman from the beginning)
Zero already appears to be sidelined with her computer room, even though it was clear she was being positioned as a main interest for a while there.
Lyra is another very cute character, but I'm worried the same thing will happen to her.