The year is 1996, one year after the events of Tenchi Universe. After being defeated by the Jurai Emperor and the Galaxy Police (GXP) centuries ago, the monstrously-powerful Super A-1 class criminal, Kain, was permanently imprisoned in a subspace container of the GXP's headquarters. However, Kain managed to escape and used his time-space powers to destroy GXP HQ. He then set his sights on Earth and travels back in time to take his revenge on Jurai's royal family. Before the GXP was wiped out, they managed to broadcast a warning about Kain's escape, but due to its weak signal, both Kiyone and Mihoshi didn't comprehend the gravity of the situation.
At the Masaki house, Tenchi was watching an old film of his mother, Lady Achika, with Ayeka, Ryoko, and Sasami. This was the first time the girls get to see how Tenchi's mother looks like when she suddenly vanished from the film. As everyone was tried to understand the situation, the Misaki Shrine, the house, and Tenchi all began to fade out of existence. Coincidentally, Washu noticed a change in the space-time continuum and quickly devised a temporal shield to protect everyone from the effects of the changed time line. Washu theorizes that someone tampered with the established timeline and wiped out the Misaki family. To prevent Tenchi from vanishing, Washu devised a special temporal net to prevent Tenchi from fading out of time. However, the shield is only a temporary solution; Washu sends the rest of the group back to 1970 (via a highly experimental time machine) to prevent Kain from wiping out the Misaki and Juraian royal family.
In the year 1970, each of the girls assumes various covers to gain a watchful eye over Lady Achika as well as Tenchi's dad, Nobuyuki. At their high school, Ayeka and Ryoko pretends to be newly transferred students. Mihoshi is a social studies teacher and Kiyone is the school's janitor. Although it is their mission to save the Misaki family, Washu warns Tenchi of not interacting with his mother to prevent a potential temporal paradox. Still curious to monitor the situation as well as being close to his mother, he had Sasami act as his lookout to make sure it's safe.
To further increase their closeness to Achika, Ryoko and Ayeka made arrangements to live with the Misaki family as boarding guests. All of this was done due to the fact Washu couldn't pinpoint the exact time and place Achika will be killed; the group had to find various ways to be near Achika and the Misaki family to protect them. Through a special communicator outfitted for Sasami, Washu warned the group that Achika is likely to be killed within seven days, GXP HQ had been wiped out due to the escape of Kain, and that Tenchi has also seven days of protection from the temporal shield before it can't hold him anymore.
While on a field trip in Tokyo, Ryoko noticed a classmate constantly observing Lady Achika. She correctly deduced there's something wrong with him and she chased him down. It was revealed that he's an alien special ops GXP officer, here to capture Kain. However, he didn't appreciate Ryoko's intervention and even wanted to capture her. The two had a brief exchange that suggests Kain is coming to Earth and Ryoko gained a useful clue from him; their chat was short as both engaged each other in combat. Neither side gained ground and the officer cloaked himself to escape.
Later at the hotel, one day before Kain's estimated arrival, Tenchi and the whole group met at their hotel room to reconnoiter. After Washu had performed additional analysis, she was able to deduce that the GXP HQ's destruction and Lady Achika's death was related. Washu transported Kiyone back to modern times to access her ship's criminal database to read up on Kain. Based on the data they gathered, there's a strong possibility that Kain had come to take his vengeance upon the Juraian royal family for his imprisonment; Achika and the Misaki family are casualties of Kain's rage. Sending Kiyone back through 1970, the group was informed of the situation and Washu deduced that Kain is likely to strike near a large transmitter; Tenchi believes Tokyo Tower is the most likely place of attack while Achika is on a school trip there.
Washu explained that Kain was stopped by a combination of a subspace net and the Juraian Emperor utilizing his powers to stop Kain. The former emperor used all of his powers, at the price of his life, to stop Kain. Unfortunately, the powers of Jurai, even the direct descendants have weakened over time and can't be used to stop Kain. However, Washu devised special energy generators to temporarily create Juraian powers to entrap Kain. Because of Jurai's unique energies, only special places can be used to channel them and Tenchi realized it is related to Five Color Fudo Temples; the group is to split and activate the generators while Tenchi covertly watches over his mother. It was also around this time that Achika suffered a severe headache and collapsed, a suggestive symptom that preludes to her later demise.
On the day of Kain's arrival, the ladies dispersed throughout Tokyo to activate each of the Juraian energy generators at each of the Fudo Temples. Tenchi had the main generator on him and he stands closely to his parents. While riding on the elevator to the top of the tower, Kain attacked the elevator and Achika lost consciousness. Unwilling to see his mother harmed, Tenchi looked after her even though it could risk a paradox. Just as Kain was about to strike, the special ops GXP officer confronted Kain and he was ripped to pieces. Tenchi arrived and gave the generator to his father and asked him to activate it at the center of the tower while he faced him in combat.
While being pressed back, Tenchi exclaimed to Kain to stay away from his mother. It was then Achika stood against Kain. Just as Kain was about to take out Achika, Nobuyuki activated the generator and trapped Kain into another dimension. Unfortunately, Kain also dragged both of Tenchi's parents into the sub-space trap with them. Desperate to save his parents, Tenchi begged Washu to help him save them and she theorized a way of locking onto Achika's brainwaves for Ryoko to lock onto and teleport them there. However, it would also mean a confrontation with Kain.
Facing Kain would require drastic measures. Washu suggests to use the unimaginable: the dimensional cannon. Kiyone was against the idea as the cannon can destroy a small galaxy, but Kiyone relented as they're aware of Kain's powers. Using a special device, Tenchi locked onto Achika's brainwaves. It was around this time Achika activated her Juraian powers to face Kain; she also realized Tenchi is her son. Just as Kain was about to absorb Tenchi's dad, Tenchi arrived with Ayeka and Ryoko to stop Kain. Tenchi faced Kain in battle, but he wasn't strong enough and lost consciousness. Dropping his sword in combat, Achika picked up Tenchi's sword and enhanced its powers, strong enough to cut down Kain and defeating him.
Time was running out, the dimensional portal that opened for the trio to rescue Tenchi's parents was closing and Kiyone is poised to fire the cannon. Just as everyone returned to Tokyo Tower, Kain is shown to be still alive and clung onto Achika's hair, not letting her go. Kiyone fired the cannon and Achika managed to escape danger; Kain was vanquished. The timeline was repaired and everyone was sent back to their time. Before leaving, Ayeka had given Tenchi's parents special tags that will erase their memories of recent events. Lady Achika realizes she'll die young, but completely accepts her fate and only cares about living life to the fullest with Nobuyuki; she asks Ryoko and Ayeka to look after Tenchi as she can't be there for him when he needs her the most.
In the aftermath, the incident at Tokyo was chalked up to be an inexplicable incident. Tenchi reflected that her mother's Juraian powers could've saved her, but using it to defeat Kain had likely shorten her lifespan. However, Tenchi was happy to know that his parents had a great life together until her demise. In present time, the ladies all gathered together at the Misaki household to take a family picture of everyone together.Masami Kikuchi as Tenchi Masaki Ai Orikasa as RyokoMegumi Hayashibara as AchikaYumi Takada as AyekaChisa Yokoyama as SasamiEtsuko Kozakura as Ryo-OhkiRyūzaburō Ōtomo as KainToshiyuki Morikawa as young Nobuyuki MasakiYuko Kobayashi as WashuYuko Mizutani as MihoshiYuri Amano as KiyoneTakeshi Aono as Nobuyuki Masaki
The music for Tenchi in Love was composed by Christopher Franke (formerly of Tangerine Dream and the main composer for the Babylon 5 series).
The end theme song is Alchemy of Love, written by Franke and performed by Nina Hagen, with Rick Jude on backing vocals.
There is also an Achika version of the song, with new Japanese lyrics, and is performed by Megumi Hayashibara (Achika's Japanese voice actress). The Achika version is available on a single mini-CD (Pioneer PIDA-1033) and on the Japanese LaserDisc version of the movie, as a music video, which also features the original English version.
Tenchi Muyo in Love had its US television premiere on Sci-Fi Channel's (now SyFy) "Saturday Anime" block on August 26, 1996.
In America, it was initially released on home video in the '90s by Geneon Entertainment USA (then known as Pioneer) through Live Entertainment before they released it independently on DVD in 2003. This release was one of the few releases from Pioneer/Geneon to have THX-certified audio and video. After Geneon shut down in 2007, Funimation Entertainment announced the license of the movie, along with a handful of other Geneon titles. The movie is distributed by Madman Entertainment in Australia and New Zealand and by MVM Films in the United Kingdom. It was released on Blu-ray Disc in North America in December 2012 by FUNimation in a box set with the other Tenchi movies.