NewsgalleryBoris Johnson takes out the 10-year-old schoolboy as he raced down the mini turf pitch in TokyoBookmarkShareNewsByNathan Spendelow11:47, 15 OCT 2015Mayor of London Boris Johnson joins a Street Rugby tournament in a Tokyo street with school children and adults to mark Japan hosting 2019 Rugby World Cup (Image: PA)1 of 8Mayor of London Boris Johnson joins a Street Rugby tournament in a Tokyo street with school children and adults to mark Japan hosting 2019 Rugby World Cup (Image: PA)2 of 8Mayor of London Boris Johnson joins a Street Rugby tournament in a Tokyo street with school children and adults to mark Japan hosting 2019 Rugby World Cup (Image: PA)3 of 8Mayor of London Boris Johnson joins a Street Rugby tournament in a Tokyo street with school children and adults to mark Japan hosting 2019 Rugby World Cup (Image: PA)4 of 8Mayor of London Boris Johnson joins a Street Rugby tournament in a Tokyo street with school children and adults to mark Japan hosting 2019 Rugby World Cup (Image: PA)5 of 8Mayor of London Boris Johnson joins a Street Rugby tournament in a Tokyo street with school children and adults to mark Japan hosting 2019 Rugby World Cup (Image: PA)6 of 8Mayor of London Boris Johnson joins a Street Rugby tournament in a Tokyo street with school children and adults to mark Japan hosting 2019 Rugby World Cup (Image: PA)7 of 8Mayor of London Boris Johnson joins a Street Rugby tournament in a Tokyo street with school children and adults to mark Japan hosting 2019 Rugby World Cup (Image: PA)8 of 8