It a yaoi manga where the uke is sex friends with the seme and the uke is secretly in love with, him but the seme loves someone else, a close friend of his from school. The ukes ends up in an accident with the guy the seme likes and pretends they "switched bodies". The guy the seme likes is in a coma and the uke pretends to be him and the seme believes him from some book he showed him. He then finds out later that the sex friend uke was also in the same school like him and the dude he likes. Then the dude that the seme likes wakes up from his coma and he finda out the uke was faking about the "body switch" since he loved him and just wanted to be with him. Hope this is enough info kind of bad on exllaining things. Thank you!

Kakkou no Yume by Tamekou?