Is Watanare a realistic depiction of teen romance? No. Does it have a compelling story with deep, multidimensional characters? Not really. But is it fun? Heck yeah, it's fun. And that's all I can really ask from a piece of media.
Watanare draws from the classic harem romcom formula, except the loner otaku protagonist is a girl. Renako, our harem queen, finds herself surrounded by four perfect girls of different flavors, all somehow falling in love with her and fighting each other for her hand.
There are funny moments, saucy moments, and occasional character drama moments, all memorably blended together into a great manga adaptation. If you want "realistic" or "wholesome," leg it somewhere else. But if you just want some yuri harem fun, Watanare is absolutely for you.
Disclaimer: I only read the official print volumes as they come out, so yes I'm behind on the English scanlations. I just prefer reading paper books whenever possible. I'd recommend picking up the physical copies if you can.