The Kanagawa's Lottery is the oldest and highest paying lucky draw amongst all Japanese Takara-kuji Lotteries. Takara-kuji is The Official Japanese Lottery that can be held legally in Japan.
In fact, with the exception of The Spanish El Gordo Draw, it is The Biggest Lucky Draw in the World. Tickets can be found legally in all over Japan.
Usually the ticket sellers combine together with other Japanese Lotteries so buyers can be freely choose which tickets they are interested to buy.