Norinori
Background
The specific origin of this puzzle is not known, but it may have first appeared in a Nikoli publication.
Puzzle and Goal
An unsolved puzzle consists of a square grid with marked regions.
The goal is to color in pairs of neighboring cells according to the rules.
Rules
The solved grid must satisfy the following conditions:
Each region has exactly two colored cells.
Each colored cell has exactly one orthogonal neighbor.
Playable Online