Nice hike with stuff to see along the way! Instead of taking the 500-yen ropeway up the mountain, we hiked up which took around an hour. There are a couple of trails. The entrance for the path we took is less than a 10-minute walk from Hamakanaya Station 浜金谷 / Kanaya (Tokyo Bay) Ferry Terminal, a 40-minute ferry ride across the bay plus a 10-minute bus ride to Kanagawa’s Kurihama Station 久里浜駅 (Bus Stop# 2 to the ferry port). There is one ferry per hour and it seems to be timed pretty well with the bus. Timetables can be found online.
The entrance to the trail is before the entrance to the ropeway. You turn left into a small road when you see a ramen shop then turn right when you see a meat shop, where there should be signs signaling the start of the hiking trail. If you reached the ropeway entrance, you’ve gone too far. There are maps at the ropeway though. The trail we took has a lot of steps, then rocks and mud. It might be slippery and muddy after a rainy day, especially in the shade. Wearing flip-flops would not be a good idea (although I did make it wearing Fit-flops and a dress). It’s not too difficult if you’re wearing hiking or even running shoes. There are no vending machines along the way so it would be a good idea to grab some drinks at the 7-11 first. There are some vending machines at Nihonji Temple.