looked like a kite of some kind at the coast. note location
No interactions present.
It looked rather like a red kite but I don't think they are supposed to occur in Japan or if there is another similar kite in that area.
The white mark at the base of the primaries is characteristic of the race M migrans lineatus which occurs in the east Palearctic.
Lat/Lng: 34.297, 132.319