Mystery Solved:)

A winter bird, who has shown himself along an old railway track in Ojima for the last few years, has bothered Dad as he heard his calls but didn't have a chance to see him clearly from the window and finally we got him!

A male Daurian Redstart (Joubitakiジョウビタキ) was making 'feee, feee, feee, ja, ja, ja' calls, flying from one place to another quickly.

He must have arrived here a couple of days earlier. Welcome back!

Unfortunately, under the grey sky, his lovely orange breast didn't look very bright...

 but still, he is beautiful!