Lupin has his eye set on a set of unique photographic plates, which hold the key to an ancient treasure dating back to the Edo period. These plates are in the keeping of Michael Suzuki, a multi-millionaire who is about to open a water park in Tokyo. Unfortunately, two of his partners aren't in good condition at the moment: marksman Daisuke Jigen is suffering from a toothache that impedes his aim, and swordsman Goemon Ishikawa has had his prized sword stolen from him... and in Suzuki's collection! Meanwhile, Inspector Zenigata must reluctantly deal with Maria, a journalist assigned to report on the Lupin case but who would much rather report on Suzuki. However, she holds a dark secret to Suzuki's past that he is prepared to hide at any cost. And just what is the secret hidden within the plates?