I saw a pretty interesting comments on the internet says that when Hikaru becomes more human, the Yoshiki becomes more non-human. We can see that Hikaru became from being not able to feel the pain to being able to and had the feeling of himself. However, in chapter 39, the Yoshiki's mom seems have forgotten her son which may stem from the blend. Since the memories are the components of being a human, does it mean that a part of humanity has gone away in Yoshiki? Meanwhile, the memories made by Hikaru also make him more human.