so many rapey ones...sort of the opposite of what you want... had one and then realized he wasn't tsundere...just kinda an a-hole...soooo probably not haha.
http://www.mangago.zone/read-manga/ousama_ni_kiss/ ha found one....kinda a queen uke too.
http://www.mangago.zone/read-manga/no_color/ HERE, this is one of the best things.
http://www.mangago.zone/read-manga/sono_koi_ni_wa_wake_ga_aru/ oooooh this is another of the best things...not full yaoi no sex scenes...romance definitely though.
http://www.mangago.zone/read-manga/keep_out_kisaragi_hirotaka/ and this
http://www.mangago.zone/read-manga/sayonara_itoshi_no_my_friend/ seme is sweet once he realizes what the deal is...first he assumes the guy's a dick....
http://www.mangago.zone/read-manga/bukiyou_na_silent/ not so much tsundere as really socially awkward and expressionless.
http://www.mangago.zone/read-manga/koi_ni_nare/
http://www.mangago.zone/read-manga/brother_shuffle/ he's also honest though...
http://www.mangago.zone/read-manga/merry_checker/
Anyone can recommend yaoi manga with tsundere uke and gentle/sweet seme who know how to take care of the uke (=・ω・=)