I can't tell you much about the 4563 that you can't glean from the pictures in this post. The box is all in Japanese, and I can't find any info about it online. But that's ok! The only thing you really want to know is if this pencil performs well and is worth the money, right? Let's dig in.
The pencil has a soft triangular barrel. Some people aren't fans of 3 sided pencils, but I am increasingly getting more and more into them. I don't hold a pencil properly, basically everything is moved down a finger. So I hold a pencil between my thumb and middle finger, and it rests on my ring finger. The index finger acts more as a second guide that sits higher up on the barrel. I think I do this so I don't have to curl my ring and pinky fingers as far into my palm to get the writing angle I'm comfortable with. Anyway, I have been holding writing instruments this way for as long as I can remember and have never had any problem with fatigue. It seems these triangular barrels, and these pencil in particular, are geared toward teaching people the proper way to hold a pencil. There's even a hand using proper technique on the front of the box.
Inside that box are 2 different colors of pencil: 6 yellow and 6 green. These are a bright yellow and a light grass green. Very primary colors. That leads me to believe that these are somewhat marketed towards schools and children learning to hold a pencil properly. Along the 3 sides: one is blank, one is imprinted in gold with Japanese characters and has a 2B pill in white, the other just has the 2B pill. They're unfinished on both ends. No ferrule and on factory sharpened.
The wood has a nice cedar smell and sharpens beautifully. I love how the collar of a triangular pencil looks, with those nice, swooping areas up near the paint. The core is 2B, and with this being Japanese, it is very soft. All it takes is a light touch to make a dark mark. Point retention is about what you'd expect on a soft pencil. With a good eraser, words come off cleanly.
Overall, I'm a fan of this one, but there isn't any real WOW factor with this pencil. It writes well, it's got a cool shape, but I don't think I'd use it as my triangular pencil of choice. I still save that designation for the DOMS Groove Slim, which has a bit better point retention and a pretty dark mark, though not equal to this Mitsubishi 2B.
Available from Amazon, $6.18 for a box of 12 at post time.