Tenchi Masaki is an ordinary guy who accidentally releases a demon trapped in a forbidden cave. This "demon" has been imprisoned for hundreds of years, and now she wants revenge! Looks like Tenchi's in trouble!

Things get even crazier for Tenchi when a space princess take him and Ryoko captive! Looks like the poor guy will need a little help if he wants to return to Earth!

Tenchi and the girls are charged with the duty of looking after his baby cousin, Taro, for a few days. As can be expected, chaos ensues and before too long the girls have run themselves ragged. It takes Washu to show them how to care for a baby, but even under her instruction they cannot cope, so Washu takes on the job single-handedly.

Ryoko accidentally damages a robe that belonged to Tenchi's late mother. When Tenchi yells at her, he accidentally upsets Ryo-Ohki as well. The heartbroken Ryo-Ohki sulks in Washu's laboratory, where her emotions affect a colony of shape-shifting creatures (the same creatures used as a base for Ryoko and Ryo-Ohki), causing them to break out of the lab and make a beeline for Tenchi.

Zero fails in her mission to capture Washu and returns to Dr. Clay. Tenchi, Ryoko and Washu pursue her to locate and rescue the real Ryoko. When Washu confronts Dr. Clay, she reveals that she and Clay were once contenders for the director's chair at the Science Academy, but Clay was cast out for misusing his scientific talents. He tries to destroy Tenchi as a means of manipulating Washu, but Zero betrays him and he is forced to destroy his ship to make an escape.

Tenchi's life is disrupted once again when some visitors from Jurai arrive. Funaho, Tenchi's Juraian great-grandmother, and her sister Misaki, who is also Ayeka and Sasami's mother, are paying a visit to Earth. Funaho has come to see her son Yosho, and to make an interesting offer to Washu. Soon after, Misaki and Funaho's husband, King Azusa of Jurai, arrives and tells Ayeka that she must marry the man he has chosen already, Seiryo.

The mysterious warrior summoned by D3 and Tokimi is sent to Earth. Meanwhile, Tenchi reminisces about the unusual events in his life that have led him to where he is now, as well as the death of his mother ten years previously. Ryo-Ohki wanders off and gets lost in the woods. After coming to her rescue, Ryoko begins to act more affectionately towards her. The next day, the Masaki household receives a most unexpected visitor.

The woman who arrived at the Masaki house turns out to be Tenchi's sister, Tennyo. She has arrived with news that Seto Kamiki, the princesses' grandmother and self-appointed matchmaker of the Juraian royal family, has picked out a fiancée for Tenchi. Before long, Tenchi's grandmother Airi arrives...

A combination of stress and exhaustion leaves Tenchi bedridden, and Tenchi's fiancée Noike nurses him back to health. Once he recovers, Noike shows Tenchi a new experimental Juraian ship designed to be more effective against any attacking foe. Meanwhile, the Kuramitsu family have received word that Mihoshi is unhappy on Earth, and send their state-of-the-art battleship out to collect her.

Mihoshi's brother Misao develops the notion that his beloved sister is part of a harem run by Tenchi and swears to kill him. However, his adjutant, Mashisu, has other plans for the mission. Meanwhile, the princesses' grandmother, Lady Seto, arrives for a visit, and the family prepare a special meal to welcome her.

The girls fight off Mashisu and her heavy mob, and Ryoko and Ryo-Ohki take on the massive battleship the Chobimaru. Mashisu, meanwhile, is forced to confront her feelings for Misao, and she begs Misao to make a choice between her and his beloved sister.

Lady Tokimi's progeny Z finally moves against Tenchi, and an epic battle in space ensues. However, when the other two chōshin, Tsunami and Washu, discover Z's motivation for wanting to kill Tenchi, they are forced to move against their sister, bringing about a confrontation that threatens to destroy Tenchi, Z and the universe itself.

Even with Nobuyuki and Rea's wedding coming up in a few days, the Masaki household, though busy with preparations for the wedding, their everyday situation is still par for the course for the Masaki house. In space too, people connected to the Masaki house are making preparations in order to attend the wedding. Airi is battling mountains of paperwork, and Funaho, who can't attend the wedding because the survival of Yosho hasn't been made public, gives her wedding gift to Minaho. A few days before the wedding, people connected to the Masaki house gather on earth and Tenchi meets his aunt Minaho. "...she reminds me of mom..." that's Tenchi's first impression, quite natural as she's also Airi's daughter. The scent of trouble is in the air...

At the lake house in Masaki Village, the preparations for Rea's wedding are in full swing. "I wanted to be married wearing the outfit that Kiyone-sama wore." With the thoughts for the late Kiyone being poured into her wedding dress, Akie, Kei, and the others continue the preparations. Meanwhile in space, Tennyo and Mikami watch over Airi working down the mountain of documents like a demon, all the while whining about missing Tenchi. Amidst all that, Minaho had reserved Tenchi for herself and spent all day with him, culminating in taking a bath together... "I'll give him back to you tomorrow, so please let me hog him for the rest of the day." Tenchi is moved by Minaho's semblance to his mother. The night quietly progresses...

One day before Nobuyuki and Rea's wedding, the women-only "Masaki Ladies' Assembly" gets together. With her wedding to Nobuyuki, Rea will finally be able to become an official member. Right after swearing her oath to the assembly, Rea's immediately asked about how her relationship with Nobuyuki began. Meanwhile in space, left behind by everyone, Airi worked all night to finish her work and tries to get to earth, but the transportation gate doesn't work and only spits out a recorded message from Washu.

On a particular day full of tension at the Masaki house, everybody is waiting for that moment. They are waiting for their new family member who will be Nobuyuki and Rea's first child and Tenchi's brother. With the entire Masaki family standing by, Tenchi's brother "Masaki Kenshi" lets out his first cry. But for Kenshi, this already marked the beginning of a heavy fate awaiting him. A few years later -- The women lead by Seto and Washu, and the men aiming to stop the women, lead by Juraian emperor Azusa and including the "Seto inhibitor" Seina, gather to discuss Kenshi's development. While the disquieting discussions continue, Kenshi's mother Rea makes a decision.

Though the destiny-laden life brings a lot of joy to Kenshi's mother, Rea, and Tenchi, the days are also tinged with worries. Next to the soundly sleeping Kenshi, Tennyo and Rea discuss Kiyone and other family matters until the day breaks. Then it's back to the usual "day in the Masaki family" again. Young Kenshi is not weighed down by any of the gloomy worries the adults have and grows stronger every day. Meanwhile, the adults on the side of the Yamada family are also starting to begin talking about the things to come...

Kiriko discusses making Earth a permanent home for Seina and his family with her group. Meanwhile, Lady Seto dispatches Kuis to charge Seina with overseeing a proxy war on tabletop island. Tenchi and the group arrive on the island and are greeted by Seina.

Sparks erupt, multiple balls of fire illuminate the emptiness of space, and amidst all that, there is "Tabletop Island". Due to the plan Kuisu devised, Tenchi and Shou end up having to deal with the pirates. Even though he was still not used to being in space, Tenchi works with Shou and the others to contain and ship off the pirates, despite having his doubts. One day, "Miron Pham" and "Fuku" visit the Masaki family. Miron explains that the plan is to anchor Tabletop Island on earth. She further explains that with the "Paradise War" being concluded and the island having become a floating paradise, the conditions are finally met to invite the Masaki Family there. This would be an ideal place to train Kenshi. Both Tenchi and Washu are taken aback by Miron's casual words. With all sorts of thoughts on his mind, Tenchi accompanies Kenshi, Ryouko, Ayeka, and the others to Tabletop Island. There, Tenchi will be doing some soul searching...

While Tenchi and Seina thwart another attack on the island, Kenshi continues his training.

A few years after the previous episode, Kenshi continues his training against Minaho, Funaho, Misaki and Seto among them. That evening, a large gathering from the Juraian royal family, other royals, the Kuramitsu family and Seina's family meet with Tenchi and the girls to hear Tenchi's decision.

Kenshi’s training continues. He’s now able to defeat the girls on Banjo Island, but still cannot do it quick enough. He’s still no where near good enough to hold his own on Geminar. As such, Seina’s harem takes over the training to get Kenshi to the next level. Further, Tenchi’s harem also joins in the training, including a pregnant Ryoko.

The arrival of a bumbling Galaxy Police officer leads to outrageous adventures, and Tenchi's vacation to the hot springs is sure to prompt an outbreak of nosebleeds!

When a dangerous space criminal comes looking for Ryoko, Tenchi and the gang must spring into action! They'll need a spaceship to give chase, and Ryo-Ohki might be able to help!

After what happened to Tenchi, the girls are out for vengeance! Back on Earth, Sasami summons a battleship and Mihoshi sets and ancient genius free!