Yoyogi Park in Shibuya-ku is the perfect comic relief after a low-key shrine stop. With living space so tight in this city, parks are the places for club meetings and practice sessions and even play rehearsals, and Yoyogi draws all sorts of talent, from horn players to hip-hop dancers to rockabilly gangs, complete with poodle skirts and Elvis-inspired pompadours, who usually gather by the park's east side entrance on Sundays to jam to American pop music from the '50s. Somehow this scene is more satisfying than the Gothic Lolitas and Cosplay kids, costumed fans of Japanese manga and anime characters hanging out on the Harajuku bridge, but I always take my friends to see them too.
Yoyogi Park has a mellower side that's also worth exploring — areas to the north and west, past the fountain pond and central field. There's a cycling center (81-(0)3-3465-6855) northwest of the central field that rents bikes, including tandems, for just a few hundred yen (you're not supposed to go off the path, which is long and lovely) and a snack hut with tables that sells ice cream and beer. There is also a little dog run, so you're bound to see at least a few terriers decked out in rhinestones and denim or chihuahuas dressed like cheerleaders.
Yoyogi Park is open from dawn to dusk. Admission is free. Take the JR Yamanote line to Harajuku, Omotesando exit, or the Chiyoda line to Yoyogi-koen, exit 4.