Hi-Tec-C
Used by 6 peopleamazon.com ↗

“My favorite pen is the Pilot Hi-Tec-C Cavalier, which unfortunately has been discontinued by Pilot Japan.”
Bertrand Fan Interview, Engineer (Slack) · via Uses This 
“I have a lot of notebooks but mostly use Muji ones with Muji pens or Pilot Hi-Tec-C pens in .3 which are my all time favorite.”
Jessica Lord Interview, Software engineer (Atom, Electron) · via Uses This 
“I buy Pilot Hi-Tech C drawing pens (0.25 and 0.4) in bulk, as they are always difficult to get hold of (maybe because everyone buys them in bulk).”
Rhys Newman Interview, Designer (Advanced Design @ Nokia) · via Uses This