http://www.mangago.me/read-manga/nights/
http://www.mangago.me/read-manga/sairuiu/
http://www.mangago.me/read-manga/reversion/
http://www.mangago.me/read-manga/bokura_ga_koi_wo_ushinau_riyuu/
http://www.mangago.me/read-manga/the_same_time_as_always_the_same_place_as_always/
http://www.mangago.me/read-manga/only_you_only/
And here are some more, although I'm not sure whether they are what you're looking for:
http://www.mangago.me/people/tag/191091/Realistic/?page=2
Thank you so much. Two of the mangas you cited are already my favorites and realistic is exactly what I'm looking for. You're a life saver
Can anyone suggest to me yaoi mangas where the characters are simply mature. I don't mean mature as in old and experienced and all, they could be highschoolers. I mean maturity as in they don't freak out and become tomato red from just a kiss, they don't agonize themselves over what their partner could be thinking of them, they don't belittle themselves and think that they are worthless (like many ukes I see unfortunately). They have personality and a concrete sense of identity. Thank you.