Blattella nipponica

Spent a couple of hours in Oiso chasing black swallowtail type butterflies around a park, and ended up coming home with this picture.

This bug was caught by my eldest daughter. She came running up with her hand cupped over her sleeve, "I've caught you a beetle!".  She slowly lifted her hand to reveal a dark flattish insect, and I said, 'don't move... but I think it's a cockroach'. To her credit she stayed perfectly still with a look of disgust on her face for 5 minutes as I tried to compose and focus the best shot. She hardly even flinched when it ran down her sleeve onto her hand.