Kamakura (day trip) is a real time commitment — fit it in only if it's a priority.
Allow Full day.
An easy, varied day: the bronze Great Buddha, a hillside of temples, a retro tram to the beach and bamboo groves — a relaxed mix of culture and coast close to the city. The catch: the famous spots (Hase-dera, the Buddha, Komachi-dori) get very busy on weekends and the temples are spread out, so it's a lot of walking.