Many thanks to @jaaycm for sharing his photo with Keanu on twitter. From his other tweets, he appears to be based in the UK.
Many thanks to summer_chou for sharing her group photo with Keanu in London on instagram. Photo was taken at Home Slice Pizza.
Update: Many thanks to jacklwilliams12 for sharing his group photo with Keanu on instagram. Photo was taken at Home Slice Pizza in London.
Update X3: Many thanks to Martyna Wiśniewska for sharing a photo on FB.