Smew are regular winter visitors to Onuma (and also Yakumo). They tend to be a bit shy and difficult to photograph: they take flight very easily especially at Onuma.
These shots are from 2 years ago when a small group were often resting on a small unfrozen pond in late winter. It was next to the road and they often flew off and returned soon after providing lots of BIF chances.
This is one of many species that occur in the UK but are much commoner here. I only ever saw one in the UK actually.