Mouse
- Click: toggle line segment/turn
- Drag: draw the loop continuously (if supported)
- Right click: mark forbidden (X) (if supported)
Overview 
Masyu
진주 루프 퍼즐
Draw one continuous loop that obeys the rules of white and black pearls.
No numbers, no words—just pearls and pure logic that gradually locks the loop into place.
Logic PuzzleLoop Puzzle
Goal & Core Rules
Draw a single non-intersecting loop that passes through every circled cell while satisfying each circle’s constraint.
- The loop is a single closed line with no branches and no crossings.
- White circles must be passed straight through, but the loop must turn in the previous and/or next cell.
- Black circles must be turned on, and the loop must go straight through the adjacent cells before and after the turn.
- Every circle must be included in the loop.
Controls
Keyboard
- Arrow keys: move cursor (if supported)
- Space/Enter: toggle line (if supported)
- X: mark forbidden (if supported)
Touch
- Tap: toggle line
- Drag: draw loop (if supported)
- Long-press: mark forbidden (if supported)
Beginner Tips
- Start from the edges: circle rules often force the loop to avoid or hug borders in predictable ways.
- Treat black circles as “turn anchors”—they usually create long straight segments extending out.
- Whenever you place a line segment, immediately mark what becomes impossible around it to avoid contradictions.
Advanced Tips
- Use loop logic: prevent creating small closed loops or dead ends before all circles are satisfied.
- Chain constraints: a forced straight through a white circle often propagates turns several steps away.
- Look for “must-join” points where two partial paths cannot remain separate without breaking circle rules.
Origins & History
Masyu is a loop-drawing logic puzzle designed and published by Nikoli. Wikipedia notes that an early form appeared in Nikoli’s Puzzle Communication magazine under a “pearl necklace” title, later adding black circles and adopting the shorter name “Masyu.”
Sources
FAQ
Can the loop cross itself?
No. The loop must be a single non-intersecting closed curve.
Do I have to include every pearl?
Yes—every circle is a required constraint point on the loop.
What’s the biggest beginner mistake?
Creating a small closed loop too early, which prevents satisfying remaining pearls.