Kaburi Pass (顔振峠) is an easy day hike in the outskirts of Tokyo. The starting point is Agano (吾野). From there, it's around 3.6 km to the summit of the pass. It's about half road walking and half trail walking. For most of the walk, you're close to a stream, which is nice for sound and cool air, and near the top there's a view of Mount Fuji if the weather is good. At the pass, you get to a road crossing, and the road crossing has a little restaurant run by an old woman with soba and udon. I had a bowl of sansai udon.
From the pass, you have several options. You could walk down the road either direction, but I kept following the path to the north. After a lot of downhill in thick forest, the trail comes out on a road near Kuroyama Santaki (黒山三滝). From there, it's a very long road walk to Ogose Station (越生). There is also an infrequent bus that goes to the station. I walked down the road until the bus came, took it back to station, and went home.
The popular hiking destinations in Tokyo get crowded. A place like this isn't famous, and that makes it a nice choice for a lazy relaxed hike. The trail is fairly easy. There's some elevation change, but it's nothing too severe, and the forest is quiet. I only met two other hikers over the whole 10 km! At a leisurely pace, 10 km only takes two or three hours, so if you get up late and get a late start like I did, you won't have problems running out of sunlight.