As April 21st is a Saturday, if possible I'd recommend you change your Kamakura trip to a weekday, as the main attractions are often insanely crowded on the weekends. Maybe swap it with the previous day's activity, as there probably won't be too dramatic a difference between Friday and Saturday in Ginza/Roppongi/Akasaka (or even do Roppongi on Friday night, as Kamakura is pretty much dead after dark...)