It was inevitable that someone would try manga piracy on the Kindle. It's actually coming a bit late: The iTunes store is riddled with manga apps that pick up files from pirate sites like OneManga.com.
The Kindle is more of a closed system, so you have to hack it a bit, but an entrepreneur has figured it out. Manga on the Kindle is a subscription service; for $5 a month, you can download your choice of manga to your Kindle. It sounds legit, until you look at the list of available manga: Naruto, Bleach, Fullmetal Alchemist, Air Gear. No way is any American manga publisher going to let properties like that go to an obscure multi-comic app like this.
So how do they do it? At first I thought this might be published as a blog or e-zine on Amazon's Kindle service, but it's not. Basically, it's just downloads that can be configured to go on a Kindle. There's something touchingly old-school about the instructions page; it reminds me of the beginner's guides to IRC (Internet Relay Chat) that scanlation sites used to feature, back when you still had to download. It's written in the same friendly, reassuring tone, and it explains absolutely everything that will happen.
It's pretty blatant piracy, but Manga on the Kindle gets a lot of things right. They offer the most popular titles, they don't restrict it to a single publisher, and they offer a couple of first volumes for free. This last one is key: If you're going to use digital comics as a sampler, you might as well be generous. Viz wants $4.99 for the first volume of Naruto in their iPad app; Square Enix wants $5.99 for the first volume of Fullmetal Alchemist at their online manga site. In a word: No! These are first volumes of series that have been around for years; free copies are readily available through libraries, Paperback Swap, or your best friend's older brother. Charging full price for them is shortsighted and greedy, given that the publishers made their nut on these years ago.
Whoever is behind this has some good insights into what readers want. The list of available manga includes a lot of strong titles, and there are at least ten volumes of each. At five bucks a month, it's actually quite a bargain, especially since you download the manga onto your computer and therefore get to keep it forever—no fear that the Amazon folks will sneak in in the middle of the night and take it back, as they did with 1984.
I assume this will be taken down pretty quickly once the publishers notice (and assert their legal rights), but I hope someone is paying attention. I doubt this site will get much traction because of the clunky download procedure, but the guy behind it gets almost everything else right.