Mighty has long supported the front lines as the tank for the S-rank party "Fake Bravers." However, due to a trend in party composition that prioritizes attack power, the leader, Fake, deems a tank unnecessary and unilaterally expels him. While Mighty was at a loss with nowhere to go, he happens to meet a girl named Excellen who calls herself a "Hero." No one believed she was a hero, making her lose confidence, but she was actually the true Hero who received the mission from God to defeat the Demon King...!? The isekai fantasy woven by the buddy duo of a middle-aged tank boasting absolute defense and a "bokukko" hero girl begins now!!