double personality/ split
http://www.mangago.me/read-manga/hide_seek_leepado/
http://www.mangago.me/read-manga/honto_no_bokura/
http://www.mangago.me/read-manga/itsuwari_triangle/
http://www.mangago.me/read-manga/nar_kiss/
http://www.mangago.me/read-manga/pounding/
http://www.mangago.me/read-manga/adam_no_rokkotsu/
You can check the DID tag, did you mean like Multiple Personality Disorder or like two-faced?
http://www.mangago.me/tag/DID/
The seme has a split personality. Sorry that's all I remeber