I've seen a few references to people find this hard to get. It's much easier to get now as it's been released as part of the Royal Palais du Shisheido line so you can find it in Selfridges, Harrods, Harvey Nicks and in Space NKs. Or buy it online from Serge Lutens, which is offering free postage at the moment.
I've still got two old bottles but am running out and will have to rebuy soon.