Rode the Kamo river path in Kyoto many times from east of the imperial palace in the north down to near a bridge connecting to JR Kyoto station in the south. We found the east side of the river to have the smoother cycling path as the west side becomes cobbled and then runs out somewhere adjacent to Shijo-Dori or perhaps even before. Though sometimes unpaved and a little bumpy, the single gear commuting bikes we borrowed from our Ryokan handled the surface fine. Heading south at dusk.
Japanese pedestrians and most vehicles (apart from buses) were very aware and tolerant of bicycles. In Kyoto cyclists tended to confidently share the foot-path with pedestrians, though young cyclists tended to hit the road briefly to avoid pedestrians or other cyclists in times of congestion.