Hi Marc,
In this case, a photo of the entire vessel would also help.

Now, there's a question of the name (which is correct as you put it, TENYUU), but there's also the way this name is entered in AIS. And Japanese names are often entered in AIS without double letters (Osaka, for instance, although the correct way would be OOsaka).
So, here's the same situation: the name of this small pusher tug (right?

) is "Tenyuu 2", but AIS shows "Tenyu 2".
Cheers
Vlad