After losing his job and his wife, a man named Nezuta finds himself adrift with no purpose in life. His directionless existence takes a sudden turn when he randomly downloads a smartphone application called True Fighter, which allows users to engage in street fights with one another. His initial foray into the app's violent world ends in a crushing defeat at the hands of a young man named Kido and a high school girl fighter known as Lesen. Following this humbling experience, Nezuta ends up lodging at Lesens home. It is here that he finds a new goal: to grow stronger and once again become a Blue Striker. To achieve this, he begins training under Lesen and another fighter named Juki, who is identified as the child of Maki and Julietta. However, their training is soon interrupted by the sudden appearance of a mysterious figure with abnormal fighting abilities. The story is set in a contemporary world where mobile technology can dictate real-world violence, with the narrative following Nezutas struggle to reclaim his identity and strength as a Blue Striker.