Why 東南西北 is read トンナンシャーペー in this lyrics?


I expected to read this word as とうなんせいほく but the furigana indicates another
reading. I did some search but I only found information about this band:
[The東南西北](https://ja.wikipedia.org/wiki/THE_%E6%9D%B1%E5%8D%97%E8%A5%BF%E5%8C%97)

![アジアの海賊](https://i.stack.imgur.com/wJFgv.jpg)




とん・なん・しゃー・ぺー are unique readings of 東・南・西・北, respectively, used only by
Japanese [Mahjong](https://en.wikipedia.org/wiki/Mahjong) players. I
personally don't play Mahjong, but these unique readings are known to Japanese
populations. Compared to とう・なん・せい・ほく, they are closer (although not exactly
the same) to the current Chinese readings.
[国士無双](https://ja.wikipedia.org/wiki/%E5%9B%BD%E5%A3%AB%E7%84%A1%E5%8F%8C_\(%E9%BA%BB%E9%9B%80\))
soon after this line is another reference to Mahjong terms.

I think these words are there to add an "oriental" feeling to the lyrics.




That is because it is based on the Chinese pronunciation rather than Japanese.

The song is called 「アジアの海賊｛かいぞく｝」 ("Pirates of Asia") and it is about
traveling all over Asia by sea. By using the Chinese pronunciation, it gives
that great "foreign" feeling that we are known for loving.

In "normal" Japanese, the four directions themselves come in a different order
-- 「東西南北{とうざいなんぼく}」.

The 「トンナンシャーペー」 reading is also used in mahjong.

<http://stat.profile.ameba.jp/profile_images/20150113/01/0a/CL/j/o044303321421081948017.jpg>

