For what it's worth, GID is not a diagnosis in the DSM for almost 8 years at this point. I don't know how it is in Japan though, maybe they still do that. The more accepted term now is "gender dysphoria", which more accurately describes the problem as the dysphoria felt about one's body rather than the identity discrepancy itself.
In japan a GID diagnosis is still the only legal way to change your name, gender marker and legally get surgery. I learned a lot about it from the autobio manga "the bride was a boy"
