The Decision Deck

Minami Endo used to ask "did you check that?" This year, she’s learning to ask something new: "did you compare the numbers?"

A year after cracking rumors wide open in her elementary school’s Newspaper Club, Minami has started middle school — and joined the Events Committee, where the problem usually isn’t whether something’s true. It’s what to actually do, when there’s no way to know for sure.

Buy the extra tent, or don’t? Order enough snacks for a crowd nobody can count in advance? Trust an "average" satisfaction score, or dig into what it’s actually hiding? Every school event brings a new decision with no guaranteed right answer — and Nishino-sensei, the committee’s new advisor, has exactly one question for all of them: Did you compare the numbers?

Story by story, Minami and her steady, number-loving friend Yamato pick up thirteen real decision-making tools — the same kind used in business, simplified down to their essentials — and use them to size up options, weigh what’s uncertain, and make a call they can actually stand behind.

In a world where an AI-generated answer is always one search away, the harder — and more valuable — skill isn’t finding information. It’s deciding what to do with it.

Whether you read it in one sitting or one chapter a night, The Decision Deck turns "did you compare that?" into a question your whole family starts asking — about allowances, about plans, and about every decision that doesn’t come with a guaranteed right answer. A companion to The Hibari Gazette, but a complete story on its own — no previous reading required.