Xiaotu and her friends are now in the third year of junior high school. In order to get into high school, the soldiers organized a reading club and went to Xiaoli's house to review. Xiaoli, who has always had spiritual power, had a strange dream. She dreamed that the savior appeared and the world was destroyed, which made her very worried. The new enemy, the Death Variant, began to use the inner demon to look for people with "pure hearts", and that pure heart is Talisman. When three Talismans are collected, the legendary Holy Grail with extremely powerful power will appear. The first person to be attacked by the inner demon was Xiaoli. The other soldiers wanted to save her, but this time the enemy was too strong and they were defeated. Suddenly, two mysterious new soldiers appeared and eliminated the inner demon. Their purpose was also to find the heart energy crystal. Xiaotu and Xiaowei's love produced a new moon prism. Xiaotu gained a stronger new power to fight against the approaching new enemy. Atu and her friends met two new friends who were in the first year of Infinite Academy High School-the genius racing driver Tianwang Yao who dressed like a boy and the noble and elegant violinist Kaiwang Man. Everyone was fascinated by their style. The mysterious new warriors officially debuted. They turned out to be Sailor Soldiers Sailor Uranus and Sailor Neptune. However, their strength was stronger than that of the internal warriors, and their fighting methods were also very different. In the blink of an eye, it was June. Usagi's birthday came and she wanted a pair of glass shoes as a birthday gift. Xiao Wei didn't know that Usagi's birthday was coming up, so Usagi slapped him in the face. At the suggestion of everyone, Xiao Wei ran to buy the pair of glass shoes, and Usagi went to Xiao Wei to apologize. The two met on the street. Xiao Wei put on the glass shoes for Usagi, but the inner demon appeared at this time and wanted to take away Usagi's pure heart. In the chaos, the enemy Jia Anli Lante picked up Usagi's moon prism and knew Usagi's true identity. She caught Tuxedo Mask and threatened Usagi. Usagi came to Tokyo Tower and was about to hand over her pure heart to save Xiao Wei. Sailor Uranus and Sailor Neptune appeared and saved her. Jia Lilante exposed that Xiaotu was Sailor Moon. Everyone was surprised. Sailor Venus pretended to be Sailor Moon and other warriors and appeared to deceive Jia Lilante. Jia Lilante attacked Sailor Uranus and Sailor Neptune. Sailor Moon persuaded everyone to work together to save them and finally defeated Jia Lilante. Xiaotu returned to the present from the future and said that the new Queen Serenity wanted her to come here to practice. Among the internal warriors, Minako has never been the target of the inner demon. In order to prove that she also has a pure heart, she keeps donating blood in the hope of becoming the target of the inner demon. Her actions worried everyone, and even Xiaoyao and Xiaoman also paid attention to her. Finally, the inner demon appeared and took out Minako's inner crystal. Minako, who had an amazing will, actually ran to the unmanned underground parking lot with her inner crystal. Xiaotu, Xiaoyao and Xiaoman chased her to the parking lot, and then the inner demon closed all the entrances and exits. In order to save Minako, Usagi was forced to transform in front of her enemies, Yodia, Haruka, and Koman, but she still couldn't defeat her inner demon. Seeing that Minako's inner crystal was about to be taken away, Haruka and Koman couldn't help but transform into Sailor Uranus and Sailor Neptune to save Minako. The other fighters were already outside the door. Yodia threatened Minako's life and was about to attack when Minako also transformed, so everyone's identity was exposed. Yodia found the person who had the heart energy crystal, so she asked Haruka and Koman to go to the water cathedral. Inside the cathedral, Yodia caught Sailor Neptune, beat her severely, and took out her inner crystal. The first Talisman appeared, and then turned into the Deep Sea Mirror, and Sailor Neptune fell down. Sailor Uranus took out his Talisman, the Cosmic Sword, and gave it to Sailor Moon who arrived, and then fell down. Yodia snatched the Deep Sea Mirror and the Cosmic Sword and attacked Sailor Moon. The mysterious woman Pluto Setsuna suddenly appeared and transformed into Sailor Pluto. She used the third heart crystal, the gem on the scepter, to take back the Cosmic Sword and the Deep Sea Mirror. Talisman returned to the bodies of Sailor Uranus and Sailor Neptune again, and the power of the three made the Holy Grail appear. Sailor Moon and Yudiai went to grab the Holy Grail. Sailor Moon won the Holy Grail, performed a second transformation, and easily defeated Yudiai. The enemies and the external warriors all found that Sailor Moon was not the savior, so the new mission of the three external warriors was to find the savior. The warriors met Domoe Hotaru, who was the daughter of Professor Domoe Soichi of Infinite Academy and was in poor health. Professor Domoe was actually a senior cadre of the Death Mutants, and Infinite Academy was the base camp of the Death Mutants. It seemed that Hotaru's body had another person, often out of control, saying some strange words, and possessed the mysterious power to heal trauma. Chibi-Usagi and Hotaru were very good friends, and the internal warriors also agreed that they should be friends, but the external warriors had doubts about Hotaru's power. During a battle, the inner demon's attack hit Xiaoying, and the Saturn mark appeared on Xiaoying's forehead, confirming that she was the Destroyer Sailor Saturn. The outer warriors were afraid that she would destroy the world and wanted to stop her from awakening, but it was too late. Her body had been taken over by the Death Mutants, and after swallowing the inner crystal of Chibiusa, she became Mistress 9. A series of events pointed out that the Infinite Academy was the headquarters of the Death Mutants, so everyone headed to the Infinite Academy to fight the approaching darkness...