He was originally an ordinary person, but he accidentally traveled through time and became the tennis genius Echizen Ryoma, and also activated the Demon Slayer system. Relying on the powerful abilities given by the system, he made his way through the world of Prince of Tennis and helped Qing Xue dominate the national competition. However, before the cheers of victory dissipated, a strange atmosphere quietly filled the air, and ghost figures appeared in this world where there were originally only tennis duels. The boy who once sweated on the court now picks up the Nichirin Sword and uses the fighting spirit on the tennis court and the power of the demon slayer system to protect his partners and uncover the secret of the sudden appearance of demons. In the double challenge of tennis and evil demons, he will continue to write the passionate legend of Echizen Ryoma!