Along a bay coastal train line in Chiba Prefecture is a nice mountain with good views and great hiking.
We originally planned to take the cable car back down the mountain. As you can see here, it was getting late by the time we made it to the statue, and had to almost run back up the mountain - there are a lot of stairs if you go straight up the sides without taking the middle part of the 8. As I mentioned earlier, it's possible to access the mountain on foot from the south, and I recommend that as the way out if you start at the top.
Coming from the north, it's about 15 minute walk to the cable car (900 yen round trip). From the south, the trail is about 15 minutes from the train station - but I think you should expect a full extra hour getting up to the figure-eight trail. Entrance to the temple (and thus all the trails) is a steep (pun intended) 1000 yen, but I'm sure it isn't cheap keeping a temple like this in order. Access to both Hamakanaya (for the cable car) and Hota (to hike only) take more than two hours from the Tokyo area, including an 80-minute local train ride from Chiba Station. Plan on staying at least an hour, though if you want to take your time enjoying the statues and strolling down the trail you should plan for a longer stay.
With the long train trip, it might be a good idea to combine this stop with others along the peninsula. There aren't many, but you could look at Kujukuri-hama beach, Kamogawa Sea World, Mother Farm, and Tokyo German Village.