Vietnamese-born and New York-bred, Mike Matsushita had only recently moved to London because of love.
A charity for orphans has been set up in Michael Matsushita's memory
In May he left his job as a tourist guide in Vietnam and was one month into a new life with his British girlfriend in London.
It was the end of a long period of travel after he left his bank job in New York in 2001.
It included Latin America, Africa, Australia, Cambodia and Vietnam, the country his parents had fled to escape the Communists.
For the final 18 months, he was a tour guide for Intrepid Travels in Cambodia and Vietnam.
It was there he met and fell in love with English colleague Rosie Cowan. Friends said they planned to marry.
On 7 July, Mr Matushita died on the Piccadilly Line as he travelled from his home in Islington to a new job in IT recruitment.
When he was reported missing, his parents David and Muoi, and his childhood friend David Golovner, flew to London and searched hospitals for him.
But police confirmed his death from identification found at the scene.
Mr Matsushita's biological father was a South Vietnamese soldier who died during the Vietnam War.
His mother, also Vietnamese, then met US aid worker David Matsushita, who adopted the boy and moved to New York after the war.
Mr Golovner said his friend always showed a keen interest in bringing people of different cultures together.
And his work as a tour guide emphasised this, as he took Western travellers to local orphanages.
Mr Golovner told US news website Newsday: "He always said 'The kids have no money, they're barefoot, but they are always happy.'
"He wanted to find what the essence was that made them so happy and then share that with others."
With this in mind, Mr Matsushita's family and friends launched a new charity in his honour, to benefit orphans in Cambodia.
Intrepid Travel, where Mr Matsushita worked for 18 months until May, has pledged to match all donations and pay administrative costs.
Mr Golovner said: "He had a huge passion for life. As a friend, he was my brother. As a person, he was a resident of the world. He had the ability to see the wonder in everything."