Act Zero-Tuxedo Mask's Secret Birth is the final Pretty Guardian Sailor Moon special.
Usagi and Mamoru are sitting down on steps and she asks him why he became Tuxedo Mask. He flashes back to when he was a child who had ran away from home and bumped into a man who wore an outfit like Tuxedo Mask's but with a black mask rather than a white one. The man bandaged Mamoru's knee and he still has the bandage. After training for years he was finally able to transform into Tuxedo Mask and from then on he went looking for the Legendary Silver Crystal. After a long silence Mamoru says that it was all a lie but as he tries to convince Usagi that it is a lie the black Tuxedo Mask is seen brandishing bandages and then leaving.
- This is the only time in PGSM that Mamoru transforms into Tuxedo Mask and is only the second time in Sailor Moon history that he had done so, the other time being in the anime.