It's good to see "loner guy that was rejected in school but is the protagonist and OP in the isekai world" and the "chad with a million people in his harem, successful and popular in High School, and turned to 'hero' in the isekai world" are NOT arch rivals bent on killing one another. I actually like the subversion as it means more than one person has common sense around here.
Also how much you wanna bet his dad also got Isekai'd? If so, it does leave some permanent consequences for such a process existing.