my unrequited love list. http://www.mangago.me/home/mangalist/43233/ just skip over the ones i indicated 'ended with another' if that's the bad ending you are talking about
unrequited love that comes true in the end:
http://www.mangago.me/read-manga/eien_no_shichigatsu/
http://www.mangago.me/read-manga/i_want_to_become_your_bird/
http://www.mangago.me/read-manga/michizure_policy/
http://www.mangago.me/read-manga/empty_heart/
http://www.mangago.me/read-manga/toiki_yori_mo_yasashii/
http://www.mangago.me/read-manga/tonari_ni_iru_no_ni_tooi/
http://www.mangago.me/read-manga/wild_darling/
http://www.mangago.me/read-manga/uchi_no_darling_gaikokujin/
http://www.mangago.me/read-manga/king_prince/ chapter 1+2 = part 1
http://www.mangago.me/read-manga/king_prince_kaiser/ part 2
http://www.mangago.me/read-manga/koi_to_karada_wa_senaka_kara/
http://www.mangago.me/read-manga/aisaretaino/
http://www.mangago.me/read-manga/yome_ni_konai_ka/
http://www.mangago.me/read-manga/lotus_eater/
http://www.mangago.me/read-manga/second_life/
http://www.mangago.me/read-manga/wonderful_days/
http://www.mangago.me/read-manga/lotus_eater/
http://www.mangago.me/read-manga/anata_ga_oshiete_kureta_koto/
http://www.mangago.me/read-manga/koi_ni_nare/
http://www.mangago.me/read-manga/tonari_ni_iru_no_ni_tooi/
http://www.mangago.me/read-manga/toiki_yori_mo_yasashii/
http://www.mangago.me/read-manga/rush/
http://www.mangago.me/read-manga/lover_s_position/
http://www.mangago.me/read-manga/kouun_no_rihatsushi/ starts out one sided...I think romance is maybe a bit fast but this is so worth reading
http://www.mangago.me/read-manga/yume_musubi_koi_musubi/ very persistent uke...who wins. This one is a bit slower romance...seme is kinda stalked :P
http://www.mangago.me/read-manga/shizuku_hanabira_ringo_no_kaori/ persistent uke...oh its not finished though
http://www.mangago.me/read-manga/puchitto_hajiketa/ seme is the one in love...has to work pretty hard to get back in there after a breakup :P
http://www.mangago.me/read-manga/perfect_xxx/ seme practically stalks the kid...but he's weirdly wholesome and pure...romance is fairly quick but its very sweet and adorable
http://www.mangago.me/read-manga/senya_ichiya_romanesque/ another one with a persistent seme in love with an uke who wants none of it...this is more pushy though
https://www.mangaupdates.com/series.html?perpage=50&category=unrequited%2Blove%2Bbecomes%2Brequited&genre=Yaoi&orderby=rating browse through this for more
Hii ppl any suggestions on yaoi 1 sided love? It becomes mutual later in life? Tia