The requested vessel with name KOYU MARU and MMSI:0 and IMO:7396513 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
KOYU MARU 9712242 431005964 >JP NGOP6 Dec 13, 2017 05:49 UTC
KOYU MARU N/A 431003069 Jul 25, 2015 00:20 UTC

Also, you may try to find the vessel in our comprehensive Vessels Database or track this ship on the map.