Aside from Sakurajima, Sengan-en is one of those things that comes up a bunch when you’re looking for things to do in Kagoshima.
There’s a place in Kagoshima called Tmtrmnstr that sells tomato ramen, which is basically like a bizarre amalgam between a standard bowl of ramen, and spaghetti with tomato sauce.
One of the things Kagoshima is best known for is its proximity to Sakurajima, an active volcano on a nearby island (or what used to be an island — the lava from a 1914 eruption actually connected it to the mainland).