This does not make any sense. So Dai goes to a doctor's appointment while on vacation. Weird enough, but even though they just arrived, apparently he hasn't shown up for appointments with the same doctor twice before. Then the doctor (Reika) turns out to be the girlfriend of an old friend (Leiko) of his girlfriend (Loli). After the swap Leiko doesn't recognize Dai's body, but then Reika explains that she stole Dai's body because Leiko liked it so much. How can she have said she liked it if she didn't even recognize it minutes before? Later in the story it becomes apparent that Leiko doesn't even know Loli has a boyfriend, so it seems likely that she has indeed never met Dai. This storyline is a mess.
Hello and thank you for your comment. As I explained on my post in French this is my first story in comic, I committed a lot of mistakes and inconsistencies. I apologize and I will correct this for the following comic comedy that arrives soon.