When Haruna Yukawa was captured in Syria earlier this month, a video apparently released by his captors showed them pressing the Japanese man to answer questions friends say he had struggled with for years: Who are you? Why are you here?

In fact, Yukawa, 42, had first traveled to Aleppo four months earlier on what amounted to a hardship course in self-discovery, according to people who know him and his account.

Changes in Yukawa's life in suburban Tokyo had been fast and disorienting. Over the past decade, he had lost his wife to lung cancer, lost a business and his house to bankruptcy and been forced to live in a public park for almost a month, according to Yukawa's father and an online journal he maintained.