It is actually a problem to get "The original version" Because the legitimate Author of that novel is very secretive and has the idea that his works are only for Japanese... That is why that novel was released in Japanese for Japanese in a virtual store to which we Westerners do not have access...
But there are also unofficial translations (made by fans) of that novel... they are generally in English. Vietnamese or Spanish (I used the version translated into Spanish and English as the base of my fangame)
I don't know anything more than that...