Ken is a 17-year-old boy featured in the *Santa Claus in Summer* story from the *Gosho Aōyama's Collection of Short Stories*. He accidentally triggers an Earth destruction system and must deactivate it within 24 hours to prevent global catastrophe. Stricken by sudden amnesia, Ken forgets the crucial PIN code needed to stop the destruction. With Earth's fate hanging in the balance, he races against time to recover the lost memory and halt the impending doom.