Legendary since 1990 one.

Often this is  my daily carry 
Me just like to look out for some of them cheaper stuffs to recommend others.  So far I think the Platinum Pocheno is best for writing, loaded with 4B 0.5mm lead. Light, little wobble, just nice size and manufactured in Japan. I believe it is no more being made.

For those that prefer fatter mech pencil these two are recommended.  Pilot Nextage & Sakura Grosso Sharp. Both are 0.5mm.  Pilot has is a little heavier than Sakura and with hardier materials too.  Sakura has bigger barrel and cheaper by a bit because of the distribution channels used.  Pilot comes with a fixed cone tip while Sakura is fitted a slightly longish retractable one.  Them leads that comes with the Sakura are hard scratchy HB I believe so you better fill it with a bettter one before using.  Both come with soft grip and yet they are not sticky like those on Pilot Shaker 2020.

My search stop ere....

Purr fect weight and balance it almost writes on its own!

Pentel Libretto.  I believe it is marketed in this part of the world as Pentel Sterling.
There really is not that much info on this one even on the net.  More focus is given on its rollerball equivalent.  It came with decent enuff Hi-polymer pentel lead but load this with Eno 4B it really become something.

Similar yet not quite the same.  Zebra M-502 tip not retractable hence it lays graphite on paper bette than Pentel Sterling/Libretto.  M-502 is slimmer though and the clutch is made of plastic.  Both pencil uncushioned.