Look carefully at the headband, keep that in mind. Now look at that headband, this one has 4 vertical marks, while Hidan's has 3. Here is the percived mark of Hidan's headband, This is obviously NOT the rain country headband. Here is the map of the Naruto world. Notice the large unnamed areas of the map, these could easily house a new shinobi village. My conclusion: See Jiro Island south of the tea country, it is a definate triangle. Hidan's Akatsuki ring is San, meaning 3. Hidan's scythe bears 3 blades. Hidan's special jutsu involves a triangle inside a circle, which also appears on his necklace. And for good measure, here is the sea country emblem. Please note that the sea country is the series of islands just east of Jiro Island and their emblem is 3 triangles. There has to be a trend here, I believe Hidan came from a religious cult based in Jiro Island. Well, there's my 2 cents, feel free to discuss.