Co-CEO of Unruly Sarah Wood has been appointed as the Mayor’s latest tech ambassador for London, joining Tech London Advocates’ Russ Shaw, Tech City UK’s Gerard Grech and Decoded’s Kathryn Parsons.

Video ad firm Unruly, which was founded in London in 2006, was bought by News Corp for around £114m last month.

It employs some 200 people across 15 offices and is now adding Japan, the world’s third-largest advertising market, to its APAC operations, which already include Sydney and a Singapore HQ.

The firm is using this week’s trade visit to Japan, led by the Mayor of London, to unveil the plans for its new office in Tokyo.

Boris Johnson is using his next three days in Japan to meet with politicians, business leaders and investors in order to drum up investment in UK life sciences, tech and innovation.

The country was already the fourth-largest investor in London last year.

Johnson is joined on his trade mission by Passion Capital partner and government fintech envoy Eileen Burbidge and Barclays’ chief innovation officer Derek White.

Mayor of London Boris Johnson MP said: “Sarah is one of the most talented individuals working in the tech sector.

“She has built a world-class business by harnessing the best of London’s talent and innovation and is already spreading the message of our tech sector to international investors and audiences.

“Sarah is a shining example of the dynamic, entrepreneurial spirit that’s so pervasive in London and she is an outstanding ambassador.”

Of the company’s expansion into Japan Sarah Wood said: “Japan is still in the early stages of its digital video journey. Despite Japan currently having the third largest ad market in the world, only 3% of digital ad spend in 2014 was on online video.

“That’s going to change massively over the coming months, with some predicting that the Japanese online video market will be worth nearly $1bn USD by 2017.

“We want to be there from the outset to help develop the online ad industry in a way that is positive to publishers, brands and consumers.”

On her appointment, she added: “It’s a real honour to be asked to be a technology ambassador for London. London is the place to be if you want to startup and scaleup a global technology company, and I want to make sure everyone around the globe is aware of all of the opportunities the capital offers.”