There is a 9 hour time difference between the UK and Japan. In episode 7 the action is simultaneous in both places. We know this because the characters are exchanging phone calls during the day. And that's the problem: that it's daytime in both places! It could be very early morning in London and late afternoon in Japan, but the action takes several hours, and other clues indicate that it's late fall or early winter which means days are shorter and this whole scenario is not realistic.