Followed Tamagawa dori from shibuya almost all the way down to the river, with a little detour along this little brook. It was good, follow the express way is not the most scenic of routes, but it makes it easier to navigate without a map (or the Polish Pathfinder). I spotted a few koi in the ponds, not too impressive, but lots of fun flowers, bushes and water plants. If the parents come visit again, they will have to do this part of the walk.
The rules man! The rules! First of all, in case of heavy rain, or maintenance the water will not flow. Secondly, don't drop off fish here. Thirdly, don't drink the water. Check, had all 3 of them under control.
Oh, no... there's more. Don't ride bicycles or motor bikes along the walk way. Do not step into the river. Bring your rubbish with you. And if you have a dog, keep it on a leash and pick up after it. Did follow them too. There were more signs, but I thought this was enough with rules for one day.
Where Tamagawa dori met the river, I turned. They are doing quite a lot of construction work down there. Will probably be very pretty in a year or so. Followed the construction site along the river... the street became more and more narrow... Walked past a very cute cafe, now dirt road... then grass... 立ち入り禁止 (do not enter) my ass! I climbed a small fence; if they really want you to stay out, they have to make them taller I say! It all turned out very well, and a few hundred meters later there were a perfectly good (and abunai man guarded) down slope towards the path along the river.
I should have brought the camera... both white and normal heron where hanging about.
Continue to walk along tamagawa until the bridge where shinkansen crosses, then followed the road up towards Gotanda. In Gotanda, by megurogawa I turned, walked to meguro and up to the station. Then cheated, took the train 2 stations to shibuya... but mum, 31800 steps...