Nintendo CEO and President Satoru Iwata has died at the age of 55.
The company said in a statement a growth in his bile duct was the cause.
He underwent surgery in June last year to remove the growth and said in October he'd recovered sufficiently to resume his regular duties.
Iwata's death comes as Nintendo aims to double its annual operating profit in the year up to March with its long-awaited entry into smartphone games.
He'd opposed the move into mobile until the final months of his life.
Iwata had been a director at Nintendo since 2000 and its president since 2002.