Mametchi came up with a strategy to cheer up Tamagotchi Planet, who is mourning the end of the Tamagottsun. Also, a clue related to the Tamagottsun is found at Mame Mame Observatory. Tamagottsun effects are frequently happening in various places with a voice saying, "Gottsun". It seems that the Tamagottsun has peaked. Among all this, a mysterious voice calls Mametchi to prepare for operations.