exploring the arcade in this 1955 Japanese video on candy...

 This video is assumed to be from 1955:

I found it via this tweet from TOO_yoshikawa.  It is a great little video, but there are some pachinko-related rarities to be found.

First we see kids at this pachinko machine.  We can't tell much from the glimpse, but the coin slot at the right means it's a medal pachinko machine  Most machines with the slot there would pay out coins for a win.  But this isn't a video about pachinko, this is a video about CANDY, so I imagine this is a pachinko machine that dispenses sweets on a win.

The camera then cuts to a different machine, giving us wonderful footage of the machine in action!

a win causes a candy to dispense here

If this looks familiar, its because we've seen this machine before, in the Birth of Pachinko Museum by Kazuo Sugiyama:

~1940 子供パチンコ 自動菓子販賣機 (Children's pachinko confectionery vending machine) by セイコー社 (Seiko)

These machines are not gambling or tests of skill.  They are a novelty for the kids to play with.  The ball will fall out the bottom and back to the shooter lane, allowing someone to keep shooting until they hit a winning pocket and receive their confection.