http://www.mangago.me/read-manga/mainichi_seiten/
http://www.mangago.me/read-manga/ai_no_shintairiku/
http://www.mangago.me/read-manga/beast_in_the_tower/
http://www.mangago.me/read-manga/gurechawanaidene/
http://www.mangago.me/read-manga/hana_koi/
http://www.mangago.me/read-manga/kusatta_kyoushi_no_houteishiki/
http://www.mangago.me/read-manga/shounen_wa_asu_wo_korosu/
http://www.mangago.me/read-manga/tsuki_ni_mukatte_hoeru_no_sa/
http://www.mangago.me/read-manga/jinjuu_houretsuden/
http://www.mangago.me/read-manga/asterisk/
http://www.mangago.me/read-manga/seven_days/
http://www.mangago.me/read-manga/higouhou_junai/
http://www.mangago.me/read-manga/silver_diamond/
http://www.mangago.me/read-manga/koori_no_mamono_no_monogatari/
http://www.mangago.me/read-manga/love_me_baby_sasamura_gou/
http://www.mangago.me/read-manga/komatta_toki_ni_wa_hoshi_ni_kike/
http://www.mangago.me/read-manga/only_the_ring_finger_knows/
http://www.mangago.me/read-manga/la_esperan_a/
Those are my favorites.
More of complete shounen ai:
http://www.mangago.me/read-manga/link_boku_to_kimi_no_aida/
http://www.mangago.me/read-manga/aozora_no_sunda_iro_wa/
http://www.mangago.me/read-manga/deep_black/
http://www.mangago.me/read-manga/2345/ it has a sequel, but the sequel is yaoi though
http://www.mangago.me/read-manga/gimmick/ (oneshot)
http://www.mangago.me/read-manga/snow_line/
http://www.mangago.me/read-manga/sannin_gurashi/
Any suggest for shounen ai genre that have good story and already 'completed' ?
Thankyou (=・ω・=)