Synopsis

Kaede (Yoshikawa Ai) is an elementary school teacher with a passion for mysteries.
The person who first introduced her to the joy of mystery novels and detective stories was her beloved grandfather, a former elementary school principal who raised her in place of her late parents.
Now 71 years old, her grandfather is living with Lewy body dementia, a condition that sometimes causes him to see strange sights that do not exist in reality.
However, Kaede notices that whenever the conversation turns to mysteries, her grandfather becomes remarkably animated and eagerly throws himself into solving puzzles.
Realizing this, she begins bringing him everyday mysteries and small local incidents, giving him new cases to investigate and unravel.