Sex friend --> boyfriend

http://www.mangago.zone/read-manga/ano_kado_wo_magatta_tokoro/
http://www.mangago.zone/read-manga/okurete_kita_renjou/
http://www.mangago.zone/read-manga/himegoto_asobi/
http://www.mangago.zone/read-manga/mazu_wa_ubaiai/
http://www.mangago.zone/read-manga/doushitemo_furetakunai/
http://www.mangago.zone/read-manga/kiken_na_otonarisan/ 2nd story
http://www.mangago.zone/read-manga/toiki_yori_mo_yasashii/
http://www.mangago.zone/read-manga/empty_heart/
http://www.mangago.zone/read-manga/retsujou_kyoumushitsu/
http://www.mangago.zone/read-manga/mimitabu_no_riyuu/
http://www.mangago.zone/read-manga/back_stage/
http://www.mangago.zone/read-manga/toshigoro_no_otokonoko_to_are/
http://www.mangago.zone/read-manga/koi_no_mannaka/
http://www.mangago.zone/read-manga/koi_shika_dekinai_yo/
http://www.mangago.zone/read-manga/omae_de_nakya_dame_mitai/
http://www.mangago.zone/read-manga/eien_no_shichigatsu/
http://www.mangago.zone/read-manga/ikezu_kareshi_no_otoshikata/
http://www.mangago.zone/read-manga/renai_kyoutei_nukegake_nashi/
http://www.mangago.zone/read-manga/ashita_no_kimi_wa_koko_ni_inai/
http://www.mangago.zone/read-manga/sex_pistols/ ch.3-7
http://www.mangago.zone/read-manga/hey_class_president/
http://www.mangago.zone/read-manga/star_right_/
http://www.mangago.zone/read-manga/datte_asobi_desho/
http://www.mangago.zone/read-manga/karada_meate_de_warui_ka/
http://www.mangago.zone/read-manga/kimi_note/
http://www.mangago.zone/read-manga/from_701_goushitsu/
http://www.mangago.zone/read-manga/itoshii_hito/
http://www.mangago.zone/read-manga/tsumetai_taiyou/
http://www.mangago.zone/read-manga/yokubou_shounen/
http://www.mangago.zone/read-manga/junketsu_drop/
http://www.mangago.zone/read-manga/porno_superstar/

Omagod that's a lot thank you forever (づ￣ ³￣)づ

you`re welcome, have fun ヾ(❀╹◡╹)ﾉ~

here's another list. started collecting those as well http://www.mangago.zone/people/tag/49344/sex+friends/?page=1