Sailor Moon is about a klutzy, not-to-bright, cry-baby named Serena who has no prospects about her future, never studies, and is generally a ditz.

But one day she is visited by a talking cat named Luna who tells her she is the "sailor scout of the moon". When she uses a special locket and shouts "Moon Prism Power", she becomes the beautiful super hero Sailor Moon who fights for love and justice. Luna explained to her that she had to stop all the evil that had recently come to earth.

Tuxedo Mask appeared on the first episode to encourage and protect Sailor Moon, because at the time Sailor Moon had been wailing in fright from a monster. However, in later episodes, Sailor Moon ran into a girl named Amy, who turned out to be Sailor Mercury, and a girl named Raye, who turned out to be Sailor Mars.

During this time, Serena has had multiple encounters with a college student named Darien. She was totally disgusted with him, because Darien had a nasty habit of calling Serena "Meatball Head", and loved the way that bugged Serena.

By then another girl had joined them, Lita. She turned out to be the slightly over-violent Sailor Jupiter.

They learned from Luna that the imperium silver crystal was the key to the universe, and it was composed of the 7 rainbow crystals. When Queen Serenity was battling Queen Beryl a thousand years earlier, Serenity had trapped the 7 Shadow Warriors in the crystal, and sent the imperium silver crystal hurtling into space. But somehow the crystal shattered into the 7 rainbow crystals, with a Shadow Warrior locked into each piece.

Beryl sent her general Zoisite out to find the rainbow crystals that were trapped within humans. When Zoisite took the crystal from the human, the Shadow Warrior took over and battles the Sailor Scouts.

Luna gave Sailor Moon the Moon Wand, which would turn the Shadow Warriors back into the human they inhabit. During a later battle Tuxedo Mask dropped the Star Locket. Sailor Moon picked it up, and said it looked familiar.

By the time the NegaVerse had finished trying to get the rainbow crystals, Sailor Moon had 1, Tuxedo Mask had 2, and Zoisite had 4. But Zoisite stole Sailor Moon's and then tried to trick Tuxedo Mask into giving up the other 2. Zoisite captured the Sailor Scouts, with the help of her close "friend" Malachite (another of Beryl's generals), and almost got Tuxedo Mask to give her his 2 crystals.

But Sailor Venus, formerly Sailor V, arrived and freed the Sailor Scouts. They faced Zoisite and Malachite, but Beryl told them to return.

With Sailor Venus came Artemis, a white cat with a strong resemblance to Luna. Artemis had come to help out the Sailor Scouts too.

Finally, the the NegaVerse discovered that Darien was Tuxedo Mask, Zoisite convinced him to duel with her for the rainbow crystals. He agreed, and she told him to meet her at the Star Light Tower at 5:00. When Darien was on his way there, he ran into Serena. Serena immediately expected him to start calling her "Meatball Head", but to her surprise he was nice to her. Suspiciously Serena followed him.

A red bubble sent by Zoisite captured Darien and Serena, since Serena was following a little too close. Later Darien appeared in the Star Light Tower with Serena, but she was unconscious. Zoisite was across the room and demanded he do his part of the bargain and show her his 2 rainbow crystals. He brings the 2 rainbow crystals to the center and Zoisite brought her 5. Then Malachite appeared and took all the crystals. Darien threw a rose at Malachite but he disappeared and it hit Zoisite in the face.

Serena woke up and found Darien and Zoisite yelling at each other. Zoisite grew angry and disappeared telling Darien to meet her on the roof. Suddenly the room started caving in, and Darien and Serena ran into an elevator to the top floor. During the long trip to the top Serena got to know Darien, and thought he was Tuxedo Mask.

When they reached the top Zoisite sent fire down the elevator shaft and Serena transformed into Sailor Moon so she could protect Darien. Darien saw her transform and was astonished.

Zoisite mentioned Tuxedo Mask, and Darien transformed, astonishing Sailor Moon. Then Zoisite released a crystal spear aimed at Sailor Moon from behind, but Tuxedo Mask jumped in front and it hit him. Sailor Moon thought he would die and started crying. Then all 7 rainbow crystals came together in one of her tears and turned into the silver crystal. Sailor Moon turned into the Moon Princess and remembered her past.

(flashback)

A thousand years ago Princess Serena was daughter of Queen Serenity, and true love of Prince Darien (Tuxedo Mask). The Sailor Scouts were all princesses of their respected planets, but they were also a part of Serena's court. It was called the Silver Millennium, when all the planets were at peace, and everyone was happy.

But the peace ended when Queen Beryl broke out of her NegaVerse into our universe, and unleashed the awesome power of the NegaVerse to defeat the Moon Kingdom and Queen Serenity. In the middle of the battle Serena gave Darien her star locket so he would never forget her.

Queen Beryl succeeded in defeating the Moon Kingdom and killing everyone in the kingdom, including Prince Darien, Princess Serena and the Sailor Scouts. But Queen Serenity trapped Queen Beryl and the NegaVerse, and Luna and Artemis in the silver crystal. She also trapped the souls of Princess Serena, Prince Darien, and the Sailor Scouts in it.

Using the last of her strength, Serenity sent them to a new future on earth where they would be safe. Then Serenity had died.

But if Queen Beryl tried to repeat what happened there, Luna and Artemis would alert the Sailor Scouts to fight off any new threats from Queen Beryl.

(flashback ended)

Queen Beryl captured Tuxedo Mask, and erased his memory while turning him against the Sailor Scouts. Later on Sailor Moon healed him with her silver crystal and made him remember a few fragments, but Beryl captured him again and erased his memory using a stronger spell, so that the crystal couldn't heal him.

Finally, in a showdown to the death, Queen Beryl's Doom and Gloom Girls captured all the Sailor Scouts except for Sailor Moon. Beryl brought Sailor Moon to her kingdom, and Sailor Moon tried to heal Prince Darien with her crystal. It didn't work, and Prince Darien attacked her mercilessly. Sailor Moon, practically exhausted, stunned him by using her tiara. She pleaded with him, and showed him the Star Locket. Darien remembered, to Sailor Moon's delight. Beryl had been watching, and grew so angry, she threw a spear at them. Darien through his rose at Queen Beryl, breaking up the spear and stabbing Beryl through the heart. Darien apparently died (this wasn't very clear).

The NegaVerse energy rejuvenated Queen Beryl, and Sailor Moon walked out into the ice where Beryl was waiting. Sailor Moon told her to enjoy that last Beryl, it would be the last one she'd ever have.

"You'll never rule the Universe as long as I live." Sailor Moon told her calmly.

"We'd better get this over with than." Queen Beryl answered.

"Let's get to it."

"You don't know what you're up against. Goodbye Sailor Moon!" Queen Beryl yelled, and released a lot of dark energy at her. It hit Sailor Moon, and she disappeared behind a wall of ice. Beryl thought she was dead, but the ice flew apart, revealing the Princess Serena.

"I will defeat you Beryl. In the name of the Moon!"

Beryl released energy and Princess Serena shouted "Cosmic Moon Power". The energy went to the crystal and protected the Princess in a wall of energy.

Eventually the Sailor Scout's souls ask to help and join Serena using all their strength. Each of the Sailor Scouts appeared and grasped onto the crystal also, calling out their planets to give it power. All their power combined into a pink ball of energy, that destroyed Queen Beryl.

The pink energy continued to grow, expanding and covering the entire polar region. Over that, Princess Serena says that they had won, and that they finally had a chance for peace.

Serena's alarm sounded, and she jumped out of her bed when she realized she was late for school. She ran out the door and passed Lita, while Raye was sweeping the steps to the shrine, and Mina was waiting for a bus. None of them recognized each other. In school, Serena became envious of Amy's really good grades. Luna said that they had all forgotton each other, and became sad. But Artemis said they'd meet again.