Brother! I completely get where you are coming from. If there is one thing I can't stand in many a series, is that the romance is teased but never goes anywhere ... or if it goes anywhere, it's at the speed of continental drift. I'd much rather have no romance at all, than "romance" that only serves to infuriate the reader. Also can't stand harem. So thanks for this list! I can also offer a few of my own suggestions to add, if you don't mind, since you asked for them.

"After Helping “Ice Princess” From Another School, I Decided to Start as a Friend - quite similar to Omiai and I'm Gonna Live With You from your list in terms of overall feel. (the WN is translated much further than the LN). Cute romance that takes off pretty early and then there's no brakes to the ever accelerating fluff train.

"After School, at a Family Restaurant at Night, With That Girl From My Class" (The WN version. LN is barely translated) - two people with family issues hang out at a restaurant after school instead of going home, then start chatting one day and find solace and support in each other, which blossoms into quite intense and very devoted romance pretty quickly.

"The Story Of How A Beautiful Foreign Student Who Lives Next Door Started To Visit My House After I Helped A Lost Little Girl" - another one in the vein of Omiai. Guy saves a lost little 4 year old girl, finds out her big sister lives in next door apartment, they start hanging out together and the rest is history pretty quickly. Solid fluff.