Ochan no Oekaki Logic ("Ochan's Painting Logic" - Oekaki Logic is a popular alternative term in Japan for nonograms) is a nonogram/picross game for Sega Saturn, Sony PlayStation, Super Famicom and WonderSwan. It features Ochan and the rest of the Sunsoft's Hebereke crew, who present a series of picross puzzles of increasing size and difficulty.
The game sets four different functions to four face buttons - filling in a square for a definite "yes", crossing a square for a definite "no", a shaded square for an uncertain "yes", and erasing any markings to restore the square to normal. The player is allowed to tackle these puzzles in any order they wish, rather than having to unlock harder puzzles by completing the previous tiers.
The game features 300 standard puzzles which start at 5x5 and get as large as 30x30, separated into four difficulty tiers. It also features a mode where players can create their own puzzles and save them to the cart, and a mode where two players simultaneously complete a single picture, earning points for each successful "yes" and "no" square to create a competitive element.