Okimoto Shun dropped out of college to become a professional mahjong player. He plays in the mahjong parlors of Shinjuku, where he encounters many formidable opponents. When the story kicks off, his primary mahjong parlor has just gone out of business, and he is looking for somewhere else to play. In the mahjong parlors of Shinjuku, Shun will play many games of mahjong with many different people, improving his game through experience!