Originally Posted by
jib71
Are you talking about "Unagi Kikugawa" in Haneda Airport Garden?
https://tabelog.com/tokyo/A1315/A131504/13280605/
FWIW - Haneda Airport Garden is a commercial complex attached to the terminal by a covered walkway (Landside). It doesn't have any interesting gardens that I am aware of.
I would not go through immigration on a 3h 40m stop just to eat eel, much as I am a fan of unagi.
No, there are no gardens. There is an onsen in the hotel though, which could be nice. And while it is proper onsen water it is a rather artificially created spot for it