Where in Kyushu is this?

For the Kyushu Travel Guide page, it shows a rocky caldera with smoke emitting from it, with lush green mountains in the background. I've searched through countless images of each volcano/mountain range in Kyushu but cannot find it. Can someone point me to where exactly that picture was taken? It looks beautiful there!

It could be Shinmoedake

I think it's Mount Aso (precisesly Mount Aso-Nakadake), in Kumamoto prefecture. The picture seems to be taken in a little bit different angle from the ordinary angles... I'm not sure from where...

If I add, you can see one or two shelters on the other side of the edge of the crater, their form seems to be typical one at Mount Aso crater.

You can compare it with this photo here:
http://www.aso.ne.jp/~volcano/info/

Just so you know, currently you can't get anywhere near the crater (and it's been restricted about 4 years now). But if you want to see what it used to be like, try:
https://youtu.be/Tyh_nKrv5tY

I also suppose it be Shinmoedake .
https://search.yahoo.co.jp/image/search?p=%E6%96%B0%E7%87%83%E5%B2%B3&search.x=1&tid=top_ga1_sa&ei=UTF-8&aq=0&oq=%E3%81%97%E3%82%93%E3%82%82%E3%81%88%E3%81%A0%E3%81%91&at=s&ai=2TnB8GaxQIa33SCy25fAwA&ts=5726&fr=top_ga1_sa

I would also say so, especially looking at the background mountain.

For my money, Shinmoedake

If I could make a suggestion to the Site Mods then a small note to give the location of these photos would be a good addition. I have spent ages trying to locate some of the other banner pictures myself.

P.s. Notice that I am not giving my opinion in this instance :)

Now, I agree with you that it�fs Shinmoedake. We can see Karakunidake in the background.
http://jiokuro.cocolog-nifty.com/blog/2014/01/index.html

It's from the Nakadake/Takadake Trail going around the Nakadake crater at Mt. Aso. The tall mountain in the background is Kishima-dake and the smaller peak to its right is Ojo-dake. It was taken south from the Nakadake Peak along the rim of the crater trail. You turn right at Nakadake to continue up to Takadake.

https://www.google.com/maps/place/Mt.+Nakadake/@32.8807229,131.0973584...

Behind the person's backpack in the Kyushu Travel Guide picture you can see a building and a couple of walkways. All these are closed now but are the usual overlook area for the active crater.

Nakadake and Kishima-dake are now off limits. Nakadake because of volcanic activity and I'm not sure why the trail of Kishima is closed - maybe erosion prevention.

Here's a picture I took from along the same trail except looking more to the north and in winter. Kishima-dake is in the background.

https://www.flickr.com/photos/anaguma/402798325