Jishogi

Note: You do not need any knowledge of chess or shogi whatsoever in order to enjoy this game. The puzzles are 2D spatial puzzles that use chess and shogi pieces as a theme, and are more akin to something like solitaire than real-life chess or shogi. In-game help is always available and shogi pieces are color-coded so that anyone can memorize them easily. There is also an easy mode that anybody should be able to complete without trouble.

Otonashi Mayu is a bullied, weird girl. She is excellent at shogi, but extremely quiet, a little scary, and dark rumors swirl about her like thick smoke. Her worst bully, Fifield, torments her regularly, and the game begins with the start of her worst act yet.

Magic exists in this society, and Fifield is a witch. Using her power, she decides to invade Mayu's mind, with the goal of digging up all of her dark secrets, and uncovering the truth of what exactly Mayu is and why. But the mind invasion spell is fragile, and there are some things that are better left uncovered. Let things slip too far, and the hunted just might be able to become the hunter...

Part puzzle game, part walking simulator, and part visual novel, Jishogi is a story about revenge, forgiveness, talent, ethics, and sexuality. It features heavy moral ambiguity, and as much potential for evil as there is good.
Note: The game has between 3-10 hours worth of content, depending on how many endings you want to see and how fast you are with puzzles.