Hello anyone know a manga where the plot is about the seme cheating and regretting it? Or...

Um i think 10 years where I loved you the most

http://www.mangago.zone/read-manga/boundary_parks/?3oKB somewhat what you're looking for :D

http://www.mangago.zone/read-manga/hina_wa_mitsuiro_no_koi_ni_torawareru/

http://www.mangago.zone/read-manga/hina_wa_mitsuiro_no_koi_ni_torawareru/
just what you lookin for
and for drama
- my starry sky
-melting point

Try this one http://www.mangago.zone/read-manga/nigai_no_theme/, it’s good