Hm. I would be interested in this down the road. However I am completely unfamiliar with e-readers. Does anyone own an e reader? Do you like it? Can you buy japanese books for the nook or the kindle?

- Supports Japanese fonts => Kindle does, the nook normally doesn't outside .pdfs but you can fix that.
- Long battery life => roughly same battery life for all devices.
- Cheap => Doesn't fit with the other requirements. Cheap means old and with less features.
- Easy to read on => Again, most e-readers are roughly the same, but I love the built-in light so I'd vote for Glowlight or Paperwhite.
- Can have innocent books put on it in 青空文庫形式 => Most of them can.
- Fits in a pocket well => Don't put an e-reader in a pocket. Not sure where you'd find a pocket big enough for them anyway, ignoring the friction which would ruin the screen.
- Durable (it'll be in my pocket a lot) => Yeah, good luck with that.

Also, the nook can be rooted to work with both anki and dictionaries (and programs for reading japanese), but it's a bit of a cop-out since the interface is very annoying. In short, Kindle is better for having a device readily-made for reading, Nook is better if you want more options since it can be rooted into a tablet. Innocent books will keep you busy for a while, since as far as I know buying from japanese markets doesn't work.

Not sure if this can happen on the Nook, but Amazon has a habit of randomly deleting books off the user's kindles. Yes, they can do that. No, there's nothing the user can do about it.

For the record, to buy Japanese books off Amazon you need to have a Japanese Amazon account, and to have a Japanese Amazon account you need to live in Japan. While some managed to get away with it, there are records of people getting detected for using an invalid address and getting banned.

(Apparently Nook books can also get deleted, though it's a software issue)

Amazon isn't really well-known for respecting their customers, affiliates or pretty much anyone, actually. They're pretty much the poster child of corporations being the Big Bad. Part of the reason why I went with B&N actually .

I don't think e-ink can be properly replicated on other devices since it's in the build rather than the software.

Thanks for the information. To clarify, 'cheap' means around $150. The main thing is that it's not some top of the market thing, in the event that something like that exists and has all the best features (I'm assuming not, but assuming...). I did check the other threads, but most of them were a couple of years old (unless I searched poorly or something), so I wasn't sure how much of it was still relevant.

As for the pocket thing, yes, I have pockets big enough (cargo pants are acceptable everywhere I go, so unless I find myself at a formal occasion, I'll be wearing them). I would either buy or make a sleeve for it to protect the screen as well. I've carried my tablet in a similar fashion and have had no problems.

Reading all of that though, I think I might go for a Nook of some kind. I wouldn't keep a Kindle connected all that much, but I have this thing when it comes to companies refusing to let you do what you want with something you bought (which is why I mod any region-locked game consoles I buy as a principle, even if there's only one game I wanted to play that was a different region).

Although I cannot comment on the main issue here since my kindle doesn't support japanese

I can expand a bit about kindle use
1. you can fit it no problem in even a medium sized "cargo"/ side pocket

2. dont bother buying an expensive case
what I did is I went to the market area, bought some nice looking material, then went to a market- tailor to sew me a case
all in all it was like 7 bux

http://postimg.org/image/449nd9cd9/