Daydreaming of traveling to Japan

I watched a video today about an overnight ferry from Osaka to Kagoshima in Kyushu, and I wish I could go and sit by a window and watch the landmasses slowly go by. If I weren’t so close to my family and attached to my hometown, I would probably pack my bags, head to Japan, and spend the rest of my life exploring this beautiful island nation. As the next best thing, I would love to plan a month-long trip sometime in my lifetime and explore this country aboard its excellent trains starting from the far north and make my way down all the way to the south. The video left me daydreaming, but really I should be doing some research on the logistics of at least the ferry component to this dream trip of mine.