I had TV Japan running in the background, and heard mention of Ōwakudani, the steam vents above the hot-springs resort town of Hakone. The accompanying videos looked considerably steamier than when I was there.
Sure enough, Mt. Hakone just erupted a little (ash only, no reported injuries), after an increase in steam and small earthquakes since mid-April. It’s about 20 miles southeast of Mt. Fuji, and I have no idea what it means for regional activity.