The pens most professional Mangaka use. This pens nib is very elastic giving the drawer the ability to change the thickness of the line by putting more pressure of the pen. This makes this pen very hard to use but mastering it gives flavour to the lines drawn with it.
There’s no such thing as a “g pen.” It’s a dip pen. Don’t be a sucker and pay infinity dollars for a made up name when you can get the same thing at any art store in the world for literally pennies. The last time I purchased a nib at my local, it cost me 30 cents.