Ten years ago, a mysterious spatial anomaly now known as "Heaven's Gate" appeared in South America, shortly followed by the opening of "Hell's Gate" in Tokyo altering the sky and wreaking havoc on the landscape. The real stars disappeared, replaced by false stars. During this time, people possessing various special abilities — called "Contractors" — emerged, each capable of different supernatural feats. Following the disastrous Heaven's War, the United States lost its dominant position as a superpower to a mysterious organization named the Syndicate. The story revolves around a Chinese contractor codenamed "Hei" as he undertakes various espionage and assassination missions in Tokyo.

Because of the legend left by Tatsuya Uesugi, Meisei Academy High School was well-known for their strong baseball team. But 26 years after their glory, the team has not been able to keep their record and has since lost their fame.

Two stepbrothers, Souichirou and Touma Tachibana, aim to revive of the once-strong Meisei Academy baseball team and enter the National High School Baseball Championship.

Souichirou and Touma are second years in Meisei Academy Middle School. Both boys are talented baseball players. Souichirou has shown excellent skill as a catcher and batter. Though having an extraordinary skill as a pitcher, Touma no longer pitches due to a certain reason.

Once the two enter high school, they pair as a battery and aim to enter the National High School Baseball Championship!