Mariko is Elizabeth Smith's best friend having studied together at university while Mariko was on an exchange scholarship.
Mariko lives with her husband Hiroshi in Kyoto, Japan and works for a major export firm as a psychologist. Hiroshi is away a lot in Tokyo given his position at the Bank of Japan.
Mariko keeps in close contact with Elizabeth through FaceTime.
Hiroshi Fujii is married to Mariko and works at the Bank of Japan on the operations desk, managing the coordination of monetary and fiscal policy. His daily work brings him into contact with other central banks around the world and his excellent command of English (as a result of doing his PhD in an English-speaking country) means he is in daily contact with Chris Edwards.
He is often away from Kyoto because his office is in Tokyo and he commutes up and down on the Nozomi each week. Mariko is unhappy about that but tolerates it because she knows he loves his job.
Chris works as an analyst in the reserve management area of a large commercial bank. After graduation, he took a job as a graduate cadet with the central bank working on the operational desk. While working at the central bank he came into contact with Hiroshi Fujii, who was working at the Bank of Japan. They have remained friends ever since. He thinks it is a good omen that Elizabeth and Mariko are best friends.
He met Ryan through the university football team and introduced him to Elizabeth whom he knew from the University Jazz Club. He has kept in touch with them ever since and has a soft spot for Elizabeth.
He has progressive tendencies and an enquiring mind. He was amazed to discover after he began working at the central bank, and later in his current job, that banking operations are completely different to what had been taught at university.
When he visits the Smith family, Kevin can't stop grilling him about economics.