Can we take a moment and appreciate the Author having a separate boy for each girl, instead of them all being in love with the MC like 95% of modern Rom coms.
Similar thing with Polar Opposites, having proper extended cast with their own relationships is great, and allows to present different approaches to relationship, as well as more varied jokes. In a way, I'd say Kaguya-sama also used relationships in extended cast to get much more good manga material.
"That one couple destined to get together, break up and get back together a hundred and twenty-seven times before they finally give up, get married and solve the country's birthrate crisis."
More true now than ever.
The type of couple to (in the more adult future) argue and break up, somehow end up in hate sex while still arguing, move on to reconciliation sex, then to cuddly couple sex, then start arguing again before even managing to get out of the bed.