A missing Santa Claus. A crying corpse. And a brilliant mind that shines through the shadows.

Just before Christmas, twenty-seven-year-old schoolteacher Kaede is unwinding at a local bar when a festive puzzle catches her attention: the mysterious disappearance of Santa Claus.

Before the evening ends, Kaede and her friends are approached by Mr. Wagatsuma—a gentlemanly stranger who reveals he was once a pupil of Kaede’s beloved grandfather back when he was an elementary school principal. Wagatsuma brings with him a trail of baffling new cases, from a series of strange attempted suicides to rumors of a ‘crying corpse’ and seven unexplained school mysteries.

Once again, Kaede turns to her grandfather for guidance. Though he lives with the fluctuating symptoms of Lewy body dementia, his extraordinary mind flickers into brilliant focus whenever a puzzle presents itself. Working in their cherished master-and-apprentice style, grandfather and granddaughter set out to unravel the truths hidden beneath the illusions.

Steeped in classic crime nostalgia and deep emotional warmth, Lessons from My Grandfather the Master Detective, is the second installment in Masateru Konishi’s beloved series is an affectionate, cozy whodunit about memory, family, and treasuring every moment together.

Perfect for fans of Before the Coffee Gets Cold and The Thursday Murder Club.

Translated from the Japanese by Louise Heal Kawai, winner of the Lindsley and Masao Miyoshi Translation Prize.