Only some Asian women have sideways vaginas (SV). They are highly prized courtesans, usually only owned by the wealthiest and most powerful Asian men in the world. Mao Zedong had three. Another belonged to Hirohito who used her to warm his bed (rumor has it she wasn't very good looking) Pol Pot had one, she was very beautiful, but died when a supply truck ran her over.
SV Asians are indeed rare, only 200 being born every generation, so very few are ever discovered as talking about a SV is very taboo. In present times, however, this has changed drastically, as medical access increased now all the SVs are discovered. Many are owned by corporate executives across Asia, and traded in secret auctions.
There are also rumors of SV breeders, adding European, African, Indian, Middle Eastern, Eskimo, and South American SVs to the supply. This has led to a very careful accounting of SV lineage to ensure quality. Caring for SVs is pretty straight forward. You keep them away from bright lights, you keep them away from water, and you never feed them after midnight!