It can be easy to fall through the cracks of many societies, even one like Japan's that seems to have a wide safety net, beginning with Mom and Dad.
I found out just how easy when I lived on the roof of a student coop for three months in Los Angeles. I had a beater of a car as well as enough food and gas money to scrape by until, with only a single digit left in my bank account, I found a job at a Christmas-tree lot. But when my elderly Jewish boss told me I wouldn't get paid until the end of the season, a month hence, I felt the walls closing in.
I begged for an advance and, thankfully, got it. Sleep rough I could do; live on coop garbage I could not. I sold trees as though my life depended on it and made enough to not only pay back my benefactor eight-fold, but leave the roof for a one-room apartment, homeless no more.