Sorry but this manga pass from a very interesting and original situation, to clearly the moist mundane internal fantasies of the author:
- Became a girl
- Be the center of attention and desire (between his friends and/or outside)
- Have a reason to wear a school uniform and go outside
- Be to be forcibly subdued or r*p*d by somebody stronger
- Pass from the petit style to the s*x bomb woman
- Cosplay with the most fetish clothes
- Have an unrealistic reason to became an Idol
There is no way that an character like Goh will go through all that without any type of realistic mind transition, unless the author have all this in his mind, that judging by his X account, the guy is over-obsessed to become Reika
Anyway, everybody has their own reason to enjoy the manga, but... I really hoped more. Having that in mind, I really doubt other characters gonna transfrom. The history will develop around Goh/Oku being the center of everything.