buy northern kyushu pass in japan

i would like to ask whether or the northern kyushu pass could be purchased in Japan. I read it a while ago that it can but i need confirmation. and also, if it can be done, can it be activated immediately? thx a bundle!

Yes, it is possible to buy it inside Japan as explained here:
http://www.japan-guide.com/e/e2361_05.html

In the past, it was not possible.

It can be, but does not need to be activated immediately - in fact, to use it early from the following morning, or from a rural train station for example, you can set the date for when you want. If you want to use it immediately, you certainly can do that as well, but just remember that if you do that your first "day" ends at midnight.

So for example, if you activate it at 6 PM, your first "day" is just 6 hours long.

For all the important info, you really should read the official page to make sure you understand everything.
https://www.jrkyushu.co.jp/english/railpass/railpass.jsp

Be aware also that you cannot use the bullet train between Hakata and Kokura Station. Most of the best sights in Kyushu are in the northern half. Fukuoka has a number of good places, and many are not well known to even the seasoned traveler.
http://www.thejapanfaq.com/fukpic.html
https://www.youtube.com/playlist?list=PL7LcPcmoSg-j4RLa6iC7ayvBAbOn8-0...

Nagasaki is really the most interesting city on the island, and worth a couple of days. If you can see Gunkanjima, it takes 3 hours but nothing else like it except perhaps Chernobyl.
https://www.youtube.com/playlist?list=PL7LcPcmoSg-gbw2yXNLK92siHyNqSNx...
Oita and Kumamoto both have a number of great places.