Dou Yixin (right) and Chen Meng make their journey across the country on kick scooters to raise awareness about autism. Photo provided to China Daily

In every major city, they partnered with local charity organizations to launch fundraising initiatives and reached out to the community to talk to them about autism.

Dou talks about the trip in a relaxed voice, but it was no easy task. In addition to dealing with difficulties such as storms, heat and water shortages, Dou also had to take care of Chen, whose autism can lead to dramatic mood swings.

Dou encouraged Chen to communicate with people they met on the road as a way to push him to interact with others.

The book chronicles their adventures day by day through the dairies of both the men. Chen's diaries are mostly descriptive and Dou writes more about the growth of Chen and his feelings.

"Many people ask me why I like children with autism," says Chen. "Because they are innocent and pure. No matter how you treat them, they always treat you with kindness. You don't need to question their intentions. When you smile at them, they will smile back wholeheartedly."

On May 31, 2013, their journey finally came to an end, but what was originally a "farewell tour" became a new starting point for Dou. He found Chen grew throughout the journey as he had to interact with a wide range of people and deal with a variety of situations.

In 2014, he organized another journey from Chengdu to the Tibet autonomous region. This time he took Chen and another autistic young person. Three other volunteers joined the trip.

Besides organizing rehabilitation trips, Dou has also founded a new autism rehabilitation center in Beijing called Heart Speaker. He hopes to make the center self-reliant, with autistic youngsters being trained to do simple work and produce products such as handicrafts or paintings to sell.

But that is another story, for which a different book is needed.