Yosuga no Sora and Haruka na Sora Physical Edition Purchase Guide - TheRealMrWicked/CSXtoXP3 GitHub Wiki
NOTE: It is highly recommended that you purchase the digital edition of the game instead, however the physical release is provided below!
There's a Japanese law that forbids the sending of any explicit content internationally through post. However, customs are not likely to open and check every package, as their main concern is in detecting drugs, explosives etc. So you would still have a high chance of receiving your package, so long as itโs marked as "used cds" or similar. Below are ebay links for both Yosuga no Sora and Haruka na Sora, use these links to search for a listing and purchase the game.
Yosuga no Sora
YNS Regular Edition (Alternative Link)
YnS First Press Edition (Alternative Link)