Honda c50 semi auto multi plate clutch?

I have a Honda c50 bike with a wet type semi automatic multi plate clutch. The thing i can't understand is how the engine keeps running while on gear, in a stop, without touching the gear lever
which being pressed a little releases pressure from the plates.i'd like some answers concerning the operations of such clutches.

It's a centrifugal clutch. Basically the clutch friction material is forced to grip and transmit power by centrifugal force as revs rise, and is withdrawn by springs as revs drop, thus disengaging the transmission.

If I recall correctly, the mechanism on a C50 is a set of shoes spun by the engine which are forced under revs outwards to grip a drum (very like brake shoes gripping a brake drum, in fact).

I'm pretty sure that its not a basic centrifugal clutch because I have it opened in my desk an the only thing I see inside are plates and discs placed closely upon 4 springs. It seems completely different comparing to the standard centrifugal clutch you described above. Is it possible to be another type of centrifugal clutch.