Having a pet can really cheer a person up, but it can also have a much deeper impact than you might realize.
For seven-year-old Rino Kakinuma, surrounded by toy poodles and beagle pups, it is the perfect solution -- a fortnightly chance to play with her four-legged friends.
"She really likes dogs but our home is not suitable for pets," her father Shinji Kakinuma tells AFP.
"I was a bit sad for her so I looked for places where she could hang out with dogs."
Rina and her father are not alone.
The tightly packed Japanese capital can be a challenging place to keep a pet; even if your building managers allow animals, the average apartment is just 60 square metres (650 square feet) -- barely enough room to swing a cat.
That is where places like Dog Heart come in.
Just a few minutes' walk from Yoyogi Park, one of Tokyo's main green lungs, Dog Heart is part petting zoo and part rental shop.
Visitors can choose between sitting and stroking the more than 20 animals, or taking them for a walk around the park.
Half an hour of play-time costs 950 yen ($8), while 60 minutes of dog-walking will set you back 3,600 yen. Both can be extended for additional cost.
Since opening in 2012, owner Yukiko Tsuchiya, 50, says her business has been growing, with some clients coming in weekly.