I like this kind of realistic manga and plotline.

Me too, although I think this manga is best to try and read in one go.
Here is another time progression manga, that is also fairly realistic, it's written in order though unlike this one. http://www.mangago.zone/read-manga/life_senjou_no_bokura/

I remember Life Senjou no Bokura, because it was kind of realistic but one of the mc's freakin pissed me off so much, there is only one other manga that pissed me off more, were I wanted to scream and cry and not want the two to get back together and that was Complex.Here is the link if you haven't already read it: http://www.mangago.zone/read-manga/complex_manda_ringo/

Here are some others that were realistic:

http://www.mangago.zone/read-manga/yakozen/
http://www.mangago.zone/read-manga/seinen_wa_ai_o_kou/
http://www.mangago.zone/read-manga/ano_hi_no_kimi_wo_dakishimeta_nara/
http://www.mangago.zone/read-manga/kyuuso_ha_cheese_no_yume_omiru/

Thanks for the recommendations (⌒▽⌒)

HOLY S*&T! how the hell did you do that? I was just thinking today that there was a manga i wanted to reread about a guy with a broken heart and his tall friend with a hat and i was wondering "how the hell am i gonna find it??"
you have no IDEA how much time you saved me (๑•ㅂ•)و✧

Glad to help people! And have fun reading (▰˘◡˘▰)

I just saw the discussion here- thank you so much for recommending those! I've read some of them some time ago and still remember them.
Thanks once again

Well personally I do reread a lot of manga, not just favourites, it's just like I remember a scene and think about the manga it's from before I know it i'm already rereading it
ヾ(❀╹◡╹)ﾉ~
So have fun rereading, or if you are someone who does not reread manga then, hopefully, you will enjoy the ones you haven't already read.

thanks for the recommendations