It sounds more like the kind of retarded names that American producers/directors/ABC Family writers use when they want to make something Asian and specifically Japanese because anime and kung-fu movies are, "in." The kind where the Asian girl in it, exact count of (1), is named either Yuki or Kasumi. They also take random Japanese/Chinese words they really have only a miniscule understanding of the definition and culture behind, where they use for things like, "The Scroll of Fugu."

Graham, being the same kind of American, wants to sound cool and mysterious in his secret identity. Maybe he even knows what Bushido is. So he does the exact same thing, starts wearing obscenely stereotypical Japanese clothing and an Oni mask.

It's kind of the same way that Setsuna's name is Japanese (he's either Persian or Arab, yet his code name is Setsuna F. Seiei) so that Japanese viewers are meant to identify with him easier.