http://www.mangago.me/read-manga/brother_x_brother/
http://www.mangago.me/read-manga/yaizu_brothers/
http://www.mangago.me/read-manga/brother_ougi_yuzuha/ big brother is Uke tho.
http://www.mangago.me/read-manga/otouto_ni_koi_shitara/
http://www.mangago.me/read-manga/ani_no_chuukoku/
http://www.mangago.me/read-manga/bokura_wo_shihaisuru_kotoba/
http://www.mangago.me/read-manga/into_your_heart_through_the_door/
http://www.mangago.me/read-manga/toshishita_no_ryuugi/
There's more. These are just some of my favorites!
big bro as seme....lil bro as uke ⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄
It would be good at least big brother is office worker....coz i don't want any high school life incest yaoi