Sorry for the poor-quality photo. I spotted this individual right above Futakotamagawa Station. It circled a bit and then left. Both Peregrines and Goshawks have been sighted in this area. the feathers on its left-wing look like a goshawk's, but the black on the sides of its head look like a falcon's.
I agree with Goshawk. The wings are rounded and not pointed as in a Peregrine Falcon. Also the barring on the primary feathers is thicker and more pronounced like those of a Goshawk (Peregrines have very fine barring on their wing feathers). Also, the crissum is mostly white like you would expect in a Eurasian Goshawk - Peregrine Falcons have a barred crissum that wouldn't appear white.
