I elaborated before that the Flash is like a harem anime in the sense of having the protagonist be involved in multiple love triangles ditto the possibility of jealousy, breakups, STDs and unwanted pregnancies. A lot of harem anime are practically like this as the genre has taken the line “will they, won’t they” to a logical conclusion.
Archie Comics could qualify to an extent as Archie doesn’t seem to commit himself between Betty, Veronica and Cheryl Blossom. The Flash comics are no stranger to these but even if Barry has swapped Iris for Patty, it’s obvious that he’s almost always in a committed relationship with another person. Mind you his love for Iris outlasted the ones for Fiona Webb and Patty Spivot even if he dated Fiona to cope with losing her.
What makes the CW Flash different from its predecessors is that there is little to no room for a genuinely committed relationship at least at this point. Which makes it more like any other harem anime when you think about it. The author Rumiko Takahashi is generally agreed to have influenced the genre especially in her works Urusei Yatsura and Ranma 1/2, given her penchant for love rhombus relationships even though that ultimately boils down to one character committing himself to one woman (or vice versa).
Some anime like Oh My Goddess and Tenchi Muyo skip the commitment part while Oreimo went down Rumiko’s route albeit with an incestuous twist and subplot similar to what’s going on in the Flash, School Days on the other actually had one lass so jealous that she killed the lad who was cheating on her with someone else. If Caitlin Snow becomes Killer Frost, I have a feeling that she’d become the live action version of Kotonoha Katsura if the Flash were insistent on her villainous transformation.
Harem anime can be seen as what Hiroki Azuma termed database consumption, albeit in romantic action. The protagonist is an audience surrogate, who tend attracts and even accumulates a lot of otherwise stereotypical women around him. The women vie for his attention and realistically feel jealous and envious towards one another. Because the harem genre is all about “will he/won’t he date one of them?”, there is little room for a committed longterm relationship even if others like Ranma and Oreimo went for giving one of the characters a real committed relationship.
The Flash could go down that route if it weren’t for Wendy’s arrival.