An old baseball player gets another chance to live the sport he loves, but this time as a system! The son of one of Japan's greatest pitchers has a dream to follow in his father's footsteps and become a great professional, but he has a major problem, lack of talent.

Follow the journey of Shun Takahashi, a young baseball player without talent who receives the old baseball player system. Hellish training, legendary skills, impossible missions, good friends, talented rivals, and maybe luck in love. Shun and the system have a complicated relationship, but they both share the same goal, to be the greatest of all time!