pain

http://www.mangago.me/read-manga/the_horizon/

http://www.mangago.me/read-manga/the_paper_plane_which_is_under_the_rainbow/
http://www.mangago.me/read-manga/life_senjou_no_bokura/
http://www.mangago.me/read-manga/paradise_view/
http://www.mangago.me/read-manga/dekinai_ko/
http://www.mangago.me/read-manga/lonely_to_organdy/
http://www.mangago.me/read-manga/ai_no_don/

http://www.mangago.me/read-manga/saezuru_tori_wa_habatakanai/

TEARJERKER
http://www.mangago.me/home/mangalist/636848/
list is a collection of
• happy ending
• bittersweet
• sad/tragic

i recommend this for quick read
#006 http://www.mangago.me/read-manga/paradise_view/
#019 http://www.mangago.me/read-manga/hypnosis_mic_hoshi_ni_naru_made_doujinshi/

You can check the comments section if you want to know which mangas have happy/bittersweet/tragic ending

Follow the list to be updated. And if you liked the mangas/manhwas I included, please do recommend. Enjoy~ (人 •ᴗ•)