While I'm in Japan, why don't we go visit nearby South Korea during the April-May holidays in Golden Week? Golden Week brings together several Japanese holidays into a period of ~9 days, making it the longest and most used vacation time of virtually all of Japan during the whole year. So why crowd them in Japan, where Japanese travel thousands of kilometers, when I can be in Korea at the same time. I have a plan and I'm not afraid to make it happen!
That's the topic I wrote about in Czech version of this webpage, just try to click on Czech flag up on the page. Currently, it's only in Czech language. However, internet browser built-in translators are functioning, try them :) And photos don't need to be translated.