Motokazu Miyama's big fear is one probably shared by hundreds of thousands of other property-owners in Japan: What if unwelcome tenants refuse to leave after the apartment lease expires?

The 56-year-old apartment owner's concern is not completely unfounded. Unlike in the West, where written contracts are legally binding, house lease contracts are not taken literally in Japan due to a decades-old law that protects the rights of tenants. A tenant can resist an owner's eviction notice when the contract expires.

But when Miyama recently rebuilt his eight-unit studio apartment building in Tokyo's Setagaya Ward, he utilized a new law that came into effect in March and reinforces the rights of property owners to sign contracts with future tenants that require them to pack up and leave if he asks them to when the leases expire in four years.