It IS a motorcycle.. why you ask..
lets see.... first off... the engine size.. most mopeds are restricted to under 50cc...
Secondly the c70 or Cub tires are larger then scooters but smaller then mopeds. Thirdly Neither a scooter or a Moped require manual shifting of gears (has a few exceptions) and your C70 has 5 speeds. Your C70 will travel upwards of 55 miles an hour. The C70.. aslo known as Honda Cub 70 or Honda Passport is really a mix between all three.. but when they don't fall into a specialty class of moped or scooter it does fall into the more generic category of motorcycle. A scooter you sit on and normaly your feet go on top of a floor board.. however on your c70 there isn't a floor board.. (there are the wierd wind guards for your legs but your feet actualy rest on foot pegs.) Anouther reason it isn't a moped.. no pedals. One last thing.. I think the c70 is a four stroke there are a few 4 stroke mopeds.. and possibly scooters.. but not many I don't think.
(that is by definition.. in some states the certain models can fall into a moped class where engine size is less then 100cc and there are no pedal requirements.. or no stipulation for manualy shifting gears... however I'm not sure if there is any state that has all three exception to truly make your c 70 a legal moped)
A scooter is a motorcycle by most states definition.. but sometimes fall into the moped class becuase of slack moped laws... I don't think the c70 will... however to me it is more of a scooter then anything .. just due to its size.. it is pretty dang small and all that damn plastic along with the odd tire size)