Shion (bottom) is definitely in love with Rui (top) but I honestly don't think Rui is actually in love with him, at least not at first. The mangaka made him say "I've loved you even before you turned into a girl" but huhh?? no you weren't, you were clearly having fun with your girls and showed no love for him whatsoever until he turned female.
Read it for the smut but don't expect real love here
Fucked by My Best Friend