Shoma and Kizuto are hanging out at a batting center when they spot someone who looks exactly like Grotta. This mysterious person changes into sneakers, puts on a helmet, and straps on gloves—something the real Grotta would never bother doing. Despite the identical appearance, his behavior raises doubts. Is this really Grotta? Or someone else entirely? Shoma and his friends set out to uncover the truth behind the lookalike in a lighthearted and comical investigation.