hey, guys :D do you know how I could do a tag search? For example, I want to search for lo...

I think you do this:
http://www.mangago.me/tag/long haired + seme/
or something like that

That's my tag..
http://www.mangago.me/people/tag/2337/Long-haired+Seme/

Click on any tag for a manga, then the search bar is on the right column.

For example, if you go here:
http://www.mangago.me/tag/Yaoi/

you'll see the option to search tags on the right.

thank you for your helpful replies. :)