(from ebookjapan):
Big brother Taro, a promising professional boxer, is dead. His father, who suspected the Harada gang of being responsible, was also killed. Jiro takes control of "Big Brother Tank," which his father made from scrap iron, and rides into the Harada gang. What are the three secret devices equipped instead? Jiro, who got a job to support his mother, bravely confronts the suspicious incidents that occur around him with "Big Brother Tank"! An excellent work that lightly depicts the warmth and darkness of the 1950s!