Kuretake Sumi Brush Pen

I didn't know if I would like this but it's lots of fun and easy to use. It's shorter than a brush so I have to hold the pen a bit different. The brush is also shorter and less...hm... luxurious than my brushes. These bristles are synthetic.

But for on the fly practice this is terrific. I can't see being able to use it for everything but I can easily see using this every day!