Sakurakjima (Sakura-jima) another extremely active volcano of andesitic type is around 13,000 years old and until 1914 was a completely separate island, an eruption in this year filled the gap between the mainland. The volcano itself is situated within the large Aira caldera which formed around 22,000 years ago.
Taken from wikipedia, Sakurajima in 2009.
Sakurajima has been in a state of persistent activity since 1955, mainly consisting of regular vulcanism eruptions. However in the past, Sakurajima has had several plinian eruptions, the latest coming in 1914 whilst an entirely effusive eruption occurred in 1946. The current activity at the summit comes from the Minami-Dake area whilst in the past, ending around 5000 years ago it has originated from Kita-Dake.
It has been included as a Decade Volcano because of the potential dangers it poses to the voluminous numbers of nearby residents.
Global Volcanism Program
Yamanoi et al. Color measurements of volcanic ash deposits from three different styles of summit activity at Sakurajima volcano, Japan: Conduit processes recorded in color of volcanic ash. Journal of Volcanology and Geothermal Research 178 (1), pp. 81-93