Destroy All of Humanity. It Can't Be Regenerated.

July 1999, the month the world ends according to Nostradamus. Middle school boy Hajime always scores second place against his elementary school rival, the beautiful girl Sawatari. She didn't declare him her rival though, after he introduced himself as her rival when she first overtook him in elementary.
He is also an avid "Magic: The Gathering" player. While looking for new cards in the neighboring town he finds out that Sawatari plays MTG too, but in secret. She runs away though after recognizing him during a one-on-one card game.
The next day he challenges her to a duel, with a special card deck crafted against hers, promising to keep his mouth shut and do anything she says if he loses.
One thing leads to another and they finally become friends. Which he recognizes was his original goal in elementary.

The title is a play on the Magic: The Gathering card "Wrath of God"s text: "Destroy all creatures. They can’t be regenerated."