Wow I love this! When I was in school, you were seen as a cool kid if you had a four-colour BIC pen, but a amazing mechanical pencil like that Japanese one would have been much better!
Kuru Togas for sure for their rotating lead engine. The Advanced Upgrade specifically is my daily driver. The Pentel GraphGear 1000 is also a very comfortably hefty pencil. Otherwise the Pentel Orenz Nero and it's auto dispensing lead mechanism is also really cool. Rotring 600 and Staedtler 925-35 are also popular pencils that I've tried and like, but I don't own.