Awesome place 1 station past Shinagawa station... Amazing story of the 47 Ronin Samurai and their code of honor took place at this temple. Best part is, nobody really goes here. It'll get REALLY busy after next year when they release the movie about it starring Keanu Reeves. Questions? Ask away.
Not sure if it's still there but a restaurant at the base of Tokyo Tower had the best Chicken Katsu I've ever had. If you're near Tokyo Tower, look for Chicken Katsu at the restaurants nearby.