The cafe was created as a way for people to interact with animals - especially for those who might not be able to have a dog of their own right now. Perhaps a person's job requires them to work long hours and it wouldn't be practical to have a dog, or maybe their lease on their apartment has a no pets clause. The dogs at the cafe are primarily toy poodles, but there's also a Golden Retriever and a Beagle there too. You'll see the pictures of the pups there as you walk in - a bit of a description about each, their birthdays and so on!
If you want to play with the dogs, 950 yen will give you half an hour with them, and 1500 yen will give you an hour. But for 3600 yen, you can rent the pup of your choice for an hour and take them out of the cafe for a stroll - perhaps to the nearby Yoyogi Park. It could be the perfect way to sightsee with your newfound friend! Just be wary of the time, as if you do go over your allocated timeframe you will be required to pay extra.
If you plan to visit the Dog Heart Cafe - and perhaps take one of the dogs out for a stroll at Yoyogi Park, the street address is 1 Chome-45-2 Tomigaya, 渋谷区 Tokyo 151-0063. The best station to get off at is Yoyogi Koen Station, on the Tokyo Metro Chiyoda Line (green line), and the cafe is only a few minutes on foot from there.