first off I live in near Ginza in tokyo, all that happened here is some trains got delayed and things lightly shook. the rest is just relief efforts up north. everything is currently the best it could be in the situation.
I am playing on PC, the play asia link looks great though! amazon seems like they would charge a crazy amount and ship it from america.
essentially just order it via any American, Canadian or UK store that will do international shipping to Japan, just remember which version you get as American/Canadian version will likely have different patches to UK, else wise there should be no issue as a PC is not region locked. Alternatively singapore is an English speaking nation and in Asia, so if it was for a console, a Singaporian version I'd imagine would work too.