Tenchi Masaki is a college student walking through the forest who sees what appears to be a meteor falling from the sky. He investigates and finds a beautiful young woman from the wreckage of a spaceship. Her name is Ryoko and she says she is being chased by a vicious criminal who later appears in the house, meaning to attack Tenchi and Ryoko. Meanwhile, a police officer of the galaxy, Mihoshi, attempts to arrest Ryoko for being a space pirate...

Princess Ayeka, first princess of planet Jurai, regrets responding to Mihoshi's distress beacon when she meets Ryoko on Earth. The two of them go back a long way, and have been enemies for years. During her time on Earth, Ayeka finds herself falling for Tenchi, and cannot endure Ryoko's shameless flirting with him.

The Masaki home is paid another visit by an interstellar traveller in the form of Sasami, Ayeka's younger sister, who has arrived to take her sibling back home. Meanwhile, Ryoko's wrecked spaceship gives birth to a cute replacement, and the mischievous space pirate teases Ayeka by telling her that Tenchi is the father!

Ryoko becomes a bit too curious about a mysterious cave near the Masaki shrine, and despite warnings of a legendary demon that sleeps within, she ventures inside dragging the unwilling Tenchi with her. They accidentally wake the demon and are chased from the cave. However, the "demon" turns out to be Washu, a mad scientist genius who was expelled from her academy 700 years previously.

Mihoshi's Galaxy Police partner Kiyone is ordered to find her missing colleague, and heads for her last known location. Kiyone is shocked to discover her supposedly deceased partner is alive and well and living with a space pirate, two Juraian princesses and a mad scientist.

Follow a day in the life of Mihoshi and Kiyone. The Galaxy Police duo are forced to find part-time jobs to pay the rent and bills on their new apartment. But with walking disaster Mihoshi around, holding down a job for even a single day proves difficult!

Sasami and Tenchi visit the annual shrine festival, but disaster ensues when the girls bring their own brand of mayhem and catastrophe to the stalls they are running, from monster fish on Ryoko's fish catching game to Washu's uncontrollable cotton candy machine!

Washu creates a robotic duplicate of herself to help with her experiments. Unfortunately, an accident occurs when Washu's brain patterns are transferred to the robot, and it instead kills Mihoshi's personality and intelligence!

A heavy snowfall brings back memories of Tenchi's childhood, and the day his mother died. Sasami has fun playing in the snow, but the cold weather doesn't agree with everyone. When Tenchi falls ill, a little help from Ayeka's life tree Ryu-Oh is needed to restore him to health.

A ruthless interstellar bounty hunter, Nagi, arrives on Earth to claim the price on Ryoko's head. She kidnaps Tenchi and challenges Ryoko to a showdown to claim him back. However, she doesn't reckon on her spaceship cabbit, Ken-Ohki, falling in love with Ryo-Ohki!

Washu invents a dimension changing machine that allows its users to manipulate the world to their desires. Despite being forbidden by Washu from using the unfinished invention, the girls can't resist giving it a try, causing the whole family to be drawn into a maze of alternate dimensions where all their fears and fantasies are played out. The first story takes place in Heian era Japan, with Princess Ayeka as the fiancée of Tenchi, who himself is a bold warrior sent to defeat a legendary demon (who turns out to be Ryoko).

The time and space-roaming saga continues. In the second mini story, Kiyone gives up her police career for a more peaceful existence, and finds herself a job in a quiet seaside town, working at Ayeka and Sasami's tavern. The third story takes place at an ordinary Japanese high-school, with Tenchi, Ryoko and Ayeka as students and Mihoshi and Kiyone as teachers. What starts as an ordinary tale of high-school romance and rivalry ends in bizarre fantasy when Magical Girl Pretty Sammy turns up to put a stop to Ryoko and Ayeka's constant bickering.

The concluding part of the dimension-travelling tale. The fourth mini-story follows a day in the life of a drastically altered Masaki family; Tenchi and Mihoshi are husband and wife, Sasami is their daughter and Ayeka is Mihoshi's bossy sister-in-law. The fifth and final story finds Tenchi and Ryoko cast as American gangsters on the run from the law after committing dozens of daring robberies across the country. At last, Washu manages to re-establish control of the dimension tuner, but Ryoko is forced to choose between staying in her action-packed fantasy world and returning to reality.

The arrival of the Juraian military threatens the status quo of the Masaki home. Ayeka, Sasami and Ryoko are arrested, so the rest of the gang pursue the Juraian ship on which they are being held with the intention of rescuing them.

Having effected a daring escape from the Juraian military, the gang become fugitives. Meanwhile, Mihoshi and Kiyone return to headquarters, and use the opportunity to find out more about the turbulent political situation on planet Jurai. It transpires that during Ayeka and Sasami's absence, the emperor was replaced by a warrior named Yosho, who claims to be the rightful successor to the throne.

The fugitives' journey to Jurai continues, but fuel and money is running short. They decide to take jobs at a bar on a nearby planet, selling overpriced drinks to ease their financial difficulties, but the Galaxy Police are still hot on their trail.

An engine fault leaves the group stranded in deep space, and worse still, the food supplies are dwindling. Washu tries to fix the Yagami's engines, but is hindered every step of the way by Mihoshi. Meanwhile, Ryoko takes the last of the money to buy groceries on a nearby planet, but can't resist the temptations of the bars, casinos and restaurants...

Sasami is visited one night by a mysterious young girl named Mirei, who invites her back to her own ship to play. Mirei can create wonderful illusions with the wave of her hand, and she and Sasami have fun together in places from each others' memories. Meanwhile, the others, sick with worry over Sasami's disappearance, board Mirei's ship to search for her, but find the vessel has been deserted for hundreds of years.

While stocking up on fuel and supplies at a space station, the group are alarmed to discover that the Yagami has been stolen. Two teenage delinquents, Amarube and Yura, are responsible for the crime, and the gang are led on a frantic chase to retrieve their stolen spaceship.

The Yagami is in dock for more repairs, so the gang set up a café at a nearby beach resort to try and make enough money to pay the bills. Alas, trade is rather poor, but news of a swimsuit beauty contest with a big cash prize for the winner sends the girls scurrying for the changing rooms, eager for the chance to pay off their debts and prove who has the better figure!

The gang disguise themselves as schoolgirls to pass through the checkpoint into Juraian space, but Mihoshi's incompetence ruins their plan and they are forced to make an escape. However, one or two benevolent Juraians are on hand to assist them in their passage into Juraian territory.

Fleeing into a protected area of space to avoid the Juraian military, the group comes across the resting place of a pair of legendary Juraian knights, Azaka and Kamidake (after whom Ayeka's guardians were named). With the help of the guardians, Katsuhito resurrects the legendary knights, and finally reveals his true identity as the legendary Juraian warrior Yosho.

The fugitives seek refuge amongst the ruins of the Juraian imperial villa, and finally discover the identity of the man claiming to be the rightful heir to the throne of Jurai; the exiled warrior Kagato. Kagato turns up at the ruins to face Tenchi's grandfather in combat once more.

With Ryoko and Katsuhito wounded and unable to fight, Tenchi makes the decision to face his destiny, challenging Kagato and rescuing princess Ayeka. Although Ryoko does not want Tenchi to fight, she risks her own life to ensure that he reaches the royal palace safely.

Tenchi, accompanied by Azaka and Kamidake, heads deep into the royal palace to find Kagato. Azaka and Kamidake battle the two Juraian knights that protect Kagato. Tenchi himself faces Kagato in their final battle to the death, the future of Jurai and the lives of himself and his family at stake.

Tenchi narrates this epilogue to the Tenchi Universe saga, detailing the fates of everyone who was involved in the story. However, the whereabouts of Ryoko still remain a mystery.