"Logic" is the notion that regulates emotions, abilities, ideals, memories, and all other abstract aspects that comprise existence in different worlds. However, with this strength, extraterrestrial "Foreigners" are able to cross via portals infused with the Logic of their individual planets and constitute a threat to other worlds. To address this issue, the Another Logic Counter Agency (ALCA) from the human world of Septpia deploys "Logicalists," humans with the ability to create ties with Foreigners seeking peace and sharing their Logic, who are entrusted with dealing with all potential threats. Yoshichika Tsurugi has lost the capacity to employ Logic in battle after exhausting his talents two years ago, rendering him no different than an ordinary citizen. However, when he returns to the fight, his life quickly returns to the battlefield.