KyoZaNa keeps an incest list, and I know there are others who compile stories on that basis, too. Maybe you can research your preferences based on their suggestions:
brother x brother with blood relations:http://www.mangago.me/read-manga/kimi_no_iru_sekai_shikairanai/http://www.mangago.me/read-manga/sawatte_tokashite/ chapter 8-10http://www.mangago.me/read-manga/suutsu_wo_k... sakuracry
can i ask if anyone know a manga about brotherXbrother love or sisterXbrother ???
BrotherxBrother is a pretty good one (with a number of chapters) (yep - that is the title) then there is Brothers too.
Angel sanctuary!!!!
brother x brother with blood relations:
http://www.mangago.me/read-manga/kimi_no_iru_sekai_shikairanai/
http://www.mangago.me/read-manga/sawatte_tokashite/ chapter 8-10
http://www.mangago.me/read-manga/suutsu_wo_kita_akuma/ part 1
http://www.mangago.me/read-manga/ouji_to_joujin/ part 2
http://www.mangago.me/read-manga/himegoto_wa_ouji_no_tashinami/ part 3
http://www.mangago.me/read-manga/uso_to_kiss/
http://www.mangago.me/read-manga/kyoudai_biyori/
http://www.mangago.me/read-manga/doko_ga_ikenai/
http://www.mangago.me/read-manga/heart_ni_goyoujin/ chapter 2
http://www.mangago.me/read-manga/juukei_hanazono/ page 88-140
http://www.mangago.me/read-manga/tsume_to_toge/ ongoing
http://www.mangago.me/read-manga/bokudake_no_peach_sapuri/ chaper 4
http://www.mangago.me/read-manga/wana_wana_kiss/ page 114-145
brother x brother without blood relations:
http://www.mangago.me/read-manga/brother_ougi_yuzuha/
http://www.mangago.me/read-manga/bomb_heaven/
http://www.mangago.me/read-manga/toshishita_no_ryuugi/
http://www.mangago.me/read-manga/familiar/
http://www.mangago.me/read-manga/zankokuna_kimi_to_tomoni/
http://www.mangago.me/read-manga/otouto_ni_koi_shitara/
http://www.mangago.me/read-manga/melancholic_trickster/
http://www.mangago.me/read-manga/brother_x_brother/
http://www.mangago.me/read-manga/abarenbou_kareshi/ chapter 3
http://www.mangago.me/read-manga/super_lovers/
http://www.mangago.me/read-manga/ai_no_houritsu/ shota warning!
http://www.mangago.me/read-manga/devil_s_clasp/ chapter 4+5
http://www.mangago.me/read-manga/otouto_ja_irarenai/ ongoing
http://www.mangago.me/read-manga/gokudou_darling/ ongoing
http://www.mangago.me/read-manga/ichiban_chikaku_de_koi_o_suru/ ongoing
for other incest with and without blood relations you can take a look at my list:
http://www.mangago.me/home/mangalist/11763/?filter=&page=1
KyoZaNa keeps an incest list, and I know there are others who compile stories on that basis, too. Maybe you can research your preferences based on their suggestions:
http://www.mangago.me/home/mangalist/213/
For blood relationship...
Ai no DNA....