I also went with a friend to Cork, looking for his ancestors. While at Gordon College, in 1980, I spent another summer abroad, this time spending over two months visiting Belgium, England, Scotland, France, Switzerland, Italy, Austria, and Germany. The highlight, for me was the beautiful town of Firenze. I also highly recommend Brugges, Edinburgh, and of course Roma. Touring is fun, but when I moved to Japan to live for a year and a half, I really got to experience a foreign culture in depth for the first time.
Japan is full of beautiful and exciting places which can easily be reached by train and bus.
I traveled from the northern town of Sapporo to the southern town of Fukuoka and explored the parts in between. I highly recommend the celabration of Tanabata in Sendai in July. For relaxing, try the Nodo penninsula. The onsen are wonderful anywhere, but the scallop and salmon sushi are best in Hakodate.