In the mornings you'll find many other runners and walkers taking advantage of this great location but it never becomes too crowded. In addition to this you'll find musicians practicing their instruments, groups of elderly performing calisthenics, and birdwatchers trying to take snaps of the local King Fisher population.
In the evenings, when I do most of my running, the paths that runs parallel to the river are well lit, and the parks always feel safe. While there are other night time runners around, for the most part you'll be running alone.
If you continue far enough in a general westerly direction you'll intersect Kampachi Doori, after which the parks disappear and the scenery becomes a little more residential. Don't let this discourage you as just a few kilometers ahead the path terminates at Zenpukuji Kouen. Named after a temple which existed there in the past, almost half of the parkland is occupied by 2 large ponds populated by wild birds, ducks and King Fishers.
Aside from the main path running along the river there are enough side trails to provide a little variation to your route if you should find yourself running there almost daily.
Both vending machines, and toilet facilities are in plentiful supply along the river and you'll find a Mini Stop convenience store close to wear the path crosses Itsukaichi Doori.