4-day Itinerary for Kyushu/Fukuoka?

Any suggestions for a 4-day itinerary for a 1st time single female traveller to Fukuoka/Kyushu? l arrive in Fukuoka early Sat morning (prob before 9 am) and will depart 9am on Tuesday.

Check the Sunbus pass for Kyshu.
Going Kumamoto - Mt.Aso - Yufuin(Country Road Youth Hostel) Beppu and back is good in 4 days. Nagasaki is a bit out of the way and missable.

Thanks Connie! Any suggestions as to what I can do at Aso apart from going to Mt Aso? Should I just do a half day trip on the way from Yufuin to Kumamoto? I'd like to spend one day at Fukuoka city, and maybe half a day at the premium outlets.
Is this possible with your proposed itinerary?
Also, would it be better to get any travel passes before I land at Fukuoka?

http://www.japan-guide.com/forum/quereadisplay.html?0+6...
Check this link..it may be helpful

I am interested as to the comment that "Nagasaki is missable": we had planned on going there to see the A Bomb Peace park as a completion of the Hiroshima/Nagasaki experience, and were considering staying in Nagasaki to do the day trip to Arita and Imari: what are the relative merits of Fukuoka as a base or Nagasaki?

While in Fukuoka, definitely make time to check out a very cool cafe-bar in the Tenjin district called IN THE PARK (www.inthepark.jp).
Really relaxing space with balcony seating, and you'd be able to mix with some fun locals.

Don't miss Nagasaki, it's the highlight of your trip. A-bomb history. Sadder than Hiroshima.

Kumamoto castle is worth seeing. others probably beppu.

If you are young, 4 days should be enough to cover those interesting places.