Mr. Saito is a homeless who lives in Tokyo. He earns his money by selling comics which he found on the street. It seems that he can't satisfy with his living, but he enjoys it. He has his own hobby, he likes to see department fashion. At the end of the movie, the woman says that he doesn't lost himself even though he forced to live the way.
Not money makes our lives enrichment. The way enjoying our lives is to find how to enjoy ourselves.