Ginaku-ji was built as a retirement home for a retiring Shogun in the 1400's. At the time, the shoguns were based in Kamakura, but Kyoto has always been the religious and cultural capital of Japan (as well as the home of the mostly irrelevant emperor). So like most old people, he wanted to retire in a place where he could pray and do arts and crafts. He devoted his post-warlord years to moon-gazing and perfecting the art of the aforementioned tea ceremony, which I would imagine he became pretty good at after a few decades of full-time practice. The complex was built with special areas constructed for his moon gazing and tea making hobbies. I think that's a very Japanese way for warlords to retire. After he died, it became a Buddhist temple, which is what it remains today.