This is a story from 2016 (based that on the link), regardless, thanks for the ping! The three earlier topics about it and a bonus topic from the FRchives are linked below.
- Ancient Roman coins unearthed at Japan castle [09/28/2016]
- Roman coins discovered in ruins of Japanese castle [09/28/2016]
- Roman coins ID'd in Japanese ruins, but their origin baffles [10/18/2016]
- Roman jewellery found in ancient Japan tomb [06/22/2012]