Kaiketsu Zorori Movie: ZZ no Himitsu Kaiketsu Zorori the Movie: Secret of Double Z
In the film's original story, Zorori is sucked into another time with Ishishi and Noshishi. There he meets his mother during her younger days. However, she is swallowed by a mysterious monster and Zorori must team up with a treasure hunter named Zorand to save her. The film teases an explanation of the secret behind the "ZZ" mark on Zorori's costume.
[Source: Anime News Network]