It is a game played with the aim of achieving a blackjack (a sum of 21) before the opponent (dealer) does or force the dealer to go over (bust). The player receives face-down cards while the dealer has one face-down and one face-up card. The player decides to stand, fold or draw after receiving two cards.
When mentioning Japan, people often think about sushi and samurai, but the Japanese are also famous for being hardworking and humble. Most forms of gambling are banned in Japan, but online mobile gambling is growing fast in the country and it's easy to find attractive bonus offers targeting Japanese residents.