Last May, I met my childhood best friend in Tokyo . Neither of us had been to Japan before, nor had we traveled together since starting our families more than a decade earlier. When I touched down in the world’s biggest city after a whirlwind week touring Shikoku, I was still in high-powered traveler mode, armed with Google spreadsheets of all the temples and museums and shops we absolutely couldn’t miss. Kristen suggested an addition to our itinerary. She’d watched the movie "Lost in Translation" on the plane, and she was determined to do karaoke in the land of its invention, just like Bill Murray and Scarlett Johansson had. That was how, knowing nothing of the city where we’d landed, we headed to Shinjuku. After wandering the tourist-thronged streets of what must have once been an edgy red light district, we found ourselves in Champion Bar , the type of place I’d seldom patronized since my twenties: reeking of beer, packed with drunk foreigners, and very, very loud.…