Try those:
http://www.mangago.zone/read-manga/sonna_me_de_mite_kure/ (shounen-ai)
http://www.mangago.zone/read-manga/kakugo_wa_iika_soko_no_joshi/ (the girl pretty much hates him)
http://www.mangago.zone/read-manga/yellow/ (the uke is straight and the seme tries to make him fall for him)
http://www.mangago.zone/read-manga/samishigariya_no_love_letter/ (ch 3)
http://www.mangago.zone/read-manga/ai_ga_love_shite_you_nanosa/ (first story)
And this too. http://www.mangago.zone/read-manga/tokaido_hisame/
Itsuki's one-sided love somehow makes Hisame be aware of him. Anyway, this one was funny and cute.
Last Game and Koi dano ai dano
So I really want to read a romance manga where the protag is either really oblivious of their love interests advances or they don't like their love interest, like they really have to work for the attention of the protag. Any genre is fine, a few examples are like 19 days, special a or even hinekure chaser