Any good yaoi that only shows the main couple ONLY. I want the story to be based on the 1 ...

Koisuru Boukun is like that except a few extras.

http://www.mangago.me/read-manga/keep_out_kisaragi_hirotaka/
http://www.mangago.me/read-manga/hada_made_aishite/
http://www.mangago.me/read-manga/koukyuu_no_arika/
http://www.mangago.me/read-manga/otonari_no_nikushokujuu/
http://www.mangago.me/read-manga/soushoku_joushi_no_otoshikata/
http://www.mangago.me/read-manga/nichijousahan_bi_beautiful_life/
http://www.mangago.me/read-manga/kimi_ga_koi_ni_midareru/
http://www.mangago.me/read-manga/revenge/
http://www.mangago.me/read-manga/desire/
http://www.mangago.me/read-manga/retsujou_no_meikyou/
http://www.mangago.me/read-manga/okujou_fuukei/
http://www.mangago.me/read-manga/blue_sky_complex/
http://www.mangago.me/read-manga/jigoku_meguri/
http://www.mangago.me/read-manga/tsuioku/
http://www.mangago.me/read-manga/shortcut_love/
http://www.mangago.me/read-manga/koi_no_mannaka/
http://www.mangago.me/read-manga/taiyou_no_kikoushi/
http://www.mangago.me/read-manga/koi_shika_dekinai_yo/
http://www.mangago.me/read-manga/suna_no_rasen/
http://www.mangago.me/read-manga/innocent_blue/