I was looking at Amazon website to buy the kindle version but it doesn't seem to be there. It shows me only the comic. How can it be? ._.

I don't think they have kindle versions.

http://www.amazon.co.jp/dp/4048677608

If there was a kindle version, it would be under that page.

Ya, there is no ebook version of the light novels out there.

About the only option that I can think of that would let you get an ebook version would be to somehow buy the physical books, say through Yahoo Auctions, and then send them to an 'ebook creator' company. These are companies that will take a book and despine it and scan the pages in and deliver an ebook/scanned version to you. Of course, it'd probably be cheaper to buy the books through a deputy service and have them ship the physical copies to you.

Thank you both for the answers!

I've seen there is a "web" version online, probably taken from the author's website before he took it out from the website. But I'm not sure if it's so or if it was scanned and ocred. If it's the latter then it may have some mistakes so I would avoid it

Its highly unlikely to be an OCRed novel. Its more likely that its the web novel version.