FUDE DE MANNEN is a fountain pen with a special nib that allows you to easily write characters that look as if they were written with a brush.
When you hold the pen upright, you can write fine lines, and when you lay it down, you can write thick lines.
You can freely change the thickness of the lines depending on the writing angle.
It is overwhelmingly popular for being easier to hold and write with than a brush.
The [Green] pen is recommended for those who write with the pen upright, while the [Dark Blue], [Pearl White], [Pearl Pink], and [Pearl Brown] pens are recommended for those who write with the pen laid down.