William Volcanoes fall into that bucketlist “iffy” category: on one hand, wouldn’t it be cool to climb one? - but on the other, dying in pyroclastic flow, akin to jumping into a pool filled with lighted charcoal, would be unpleasant. (I’ve climbed both Unzen and Sakurajima - seems that timing, totally out of one’s control, is key.)
Unzen is in the news due to a movie regarding two volcanologists who died while doing what volcanologists do. Called “Fire of Love,” its title is as ill-chosen as that pair’s decision to venture up that day. Japan Today has a writeup: https://japantoday.com/category/entertainment/a-celebrity-volcanologist-couple-who-died-in-japan-spotlighted-in-new-documentary
Unzen was created by graben crustal faulting. Push the flesh of your forearm together to see how this works: the middle creates a valley while the edges create ridges. Debris blocks magma from the valley, causing the magma to emerge on either side. The result is Ariake Sea flanked with volcanoes (let’s not forget that Kimpo is DORMANT, not extinct).
Volcano nerds might enjoy this study: https://earth-planets-space.springeropen.com/articles/10.1186/s40623-016-0550-x