Masyu is a Nikoli logic puzzle where you draw a single continuous loop through a grid of black and white pearls.

What do black pearls mean in Masyu?

Black pearls require the loop to make a 90-degree turn, and the loop must continue straight for at least one cell in each direction.

What do white pearls mean in Masyu?

White pearls require the loop to go straight through, and at least one adjacent cell must have a turn.