It was either last month or June if I remember correctly and it was a hideo kojima interview where he was asked about different things. Even though most of the answers about Death stranding were generic, he did make mention of the game being influnced by a few aspects of Japanese folklore but didn't go much further. I'm familiar with some aspects of Japanese folklore because of my ex gf but nothing in the trailer immediately reminded of anything my ex showed me. That's why I'm even more curious about the game.