Lonely to Organdy
heartbreaking but it will put your heart back at the end
http://www.mangago.me/read-manga/kowagaranai_de_soba_ni_ite/
http://www.mangago.me/read-manga/owaranai_fukou_ni_tsuite_no_hanashi/
http://www.mangago.me/read-manga/koi_nanka_shitakunai/
http://www.mangago.me/read-manga/smells_like_green_spirit/ its actually have a happy ending but still u will feel sad.
Hybrid Child
Because of You
100% （/TДT)/ （/TДT)/
Sorekara, Kimi wo Kangaeru( the first story)
Heartbreaking Yaoi