Are Mitsuboshi drive belts original oem on an 03 Swing?

Still working on a new to me Swing. Now that my Service manual ,I found I was measuring the belt wrong. I now find the belt measures the same as new. I also find after moving it ahead it says, Mitsuboshi and part number. Is this the brand Honda used as oem ? My bike has almost 20k and I'm thinking it has been replaced. Thanks ,Ernie

Yes.

Please note that the arrows on the belt face the front of the bike.