If you're imagining something like a western anime convention then that's not entirely correct.
It's a good thing that 20 year old me didn't know what to expect.
AnimeJapan is first and foremost a trade show and the large part of the space is dedicated to big production companies. The event is professionally run in contrast to western anime conventions which are mostly organized by fans, therefore the presentation and feel is completely different.
For one all of the cosplay is designated to one area and no one in the main space is in costume unless they're working at a booth. And although there was a lot less to buy, all the merchandise was official and high quality. The great majority of it is company exhibition, it's like a one day museum of new or future things.
Unfortunately this is one of those events that if you don't speak Japanese, it isn't all that interesting.
Even as a mid tier anime enthusiast myself, I thought the time spent at the fair to be a little dull, and after about 2 hours there really isn't much left to do.
But still, around 130,000 people attend this event each year.
What made it worth the time was the limited edition merchandise that is available during these types of events that you can't get anywhere else, and the free swag of course. There was also a walk through of how anime was made which I enjoyed, along with the sneak peak at some works in production, I got to try a brand spanking new model of Wacom Tablets which delighted me.
But my favorite part was seeing the ridiculously large and chubby mascots trying to walk around normally and weave trough the crowd.
The ticket price was around ¥2,000 and the fair was opened to the public from 10AM to 5PM.
I would of course only recommend this if you love anime, I personally will skip this event from now on but I am glad I did get to experience it at least once in my lifetime as it was quite unique.
Until next time, keep stacking that Yen.