[sgxin]

Indeed this is a tough job to be in. But as she has explained that she is enjoying her work, I guess for us it is a tough job but it’s a way to make a living in Tokyo.

Definitely not as tough as those goods and human carriers climbing up Chinese mountains.
Moreover most of the weight is borne by the rickshaw wheels, and the pullers only need to exert more force when going up small slopes.
Down slope will be aided by gravity.