Him being stronger than the average delinquent wouldn't be too far-fetched, it would almost be weird if he didn't have that ace up his sleeve, but I really hope that he's way below the different captains and vice-captains.
I realize that the characters in this manga are pretty damn resilient, but God damn, those are still 3 serious cuts, at least show her getting lightheaded or something.
Don't let the art and initial premise fool you, this is surprisingly engaging. Hell, I'd even go so far as to praise the art for actually standing out amongst all the other DB fan manga out there.
Tokyo Fist is in possession of something called B-data. B-data is important. Lots of people want it.
You don't really even need to remember much more than that to enjoy the manga.