Who dicoveredfillomino number puzzle?

The Fillomino puzzle was invented by the Japanese puzzle designer Nikoli, known for creating various logic puzzles. It was first published in the magazine "Nikoli" in the early 2000s. Fillomino is a number placement puzzle that challenges players to fill a grid with numbers, ensuring that each region contains the same number of cells as the number itself. The puzzle has since gained popularity worldwide among puzzle enthusiasts.