NGL up until now Amrit was my favourite, but I decided to do and Els playthrough out of curiosity and I gotta say she is now tied with Amrit in the first spot with Ines as second and Kana on the third spot, tho all of them are pretty damn good, the only main girls I don't have much interest in pursuing are Vi and Rena, but I don't dislike them as characters. Dev did a pretty good job with the characters in this game, only minor issue I have is how some girls simply go for a kiss "out of nowhere", but again, pretty minor issue.
On the topic of the "Harem" tag, I don't feel like it would work very well, only options I would consider feasible without feeling too forced are Amrit/Ines and Amrit/Kana, but I don't find it necessary, to be honest I think it detracts from what the game seems to be setting up, at least in my eyes.