The red fish itself is not particularly exotic (Maguro); however, how it's presented definitely is.

Katsuura port in Wakayama is renowned for its Maguro, and some specialty restaurants and ryokan serve Tuna that has NEVER been frozen. This particular Katsuura-san Nama Maguro (勝浦産鮪) was served at Kumano Bettei Nakanoshima, a ryokan that's on its own island. And not far from Kumano Nachi Taisha.