Mihoshi decides to convince everyone that she is really is a top-class GP officer by recounting an important case that she and her former partner Kiyone solved some years ago. To make the story easier to follow, Mihoshi casts Tenchi and the others as the main protagonists, and proceeds to tell the tale of an ‘ultra energy' robbery- a tale that gets more farfetched with every passing sentence...
It is a lovely sunny day at the Masaki house, and, much to Ayeka's disgust, Mihoshi has done nothing all day except sleep on the porch. Ayeka cannot imagine how such a lazy person could have ever become a GP officer, but Mihoshi is adamant that she is a very competent detective with numerous important cases under her belt. And, after a little persuasion, she agrees to relate one particular tale- the case of the Ultra Energy Matter robbery.
In the middle of the "Galactic Economic Crisis", an evil space pirate began robbing Ultra Energy Matter (some unspecified type of matter with, well, ultra energetic properties). For simplicity's sake, Mihoshi decides to cast Ryoko as the space pirate, and, despite the real Ryoko's objections to this, Mihoshi continues with the story.
During her latest robbery, Ryoko was intercepted by an investigator named Tenchi, but when he tried to capture her he ended up being kidnapped himself! Mihoshi and her GP partner Kiyone (a level-headed officer who resents being partnered with the klutzy Mihoshi) were assigned to the case, with orders to track down Ryoko and retrieve both Tenchi and the Ultra Energy Matter. And they weren't alone on this mission.- apprentice detective (a.k.a. tea-maker) Sasami and Tenchi's self-appointed 'fiancé' Ayeka insisted on coming along for the ride.
After numerous hardships which Mihoshi deliberately remains vague about, the team finally reached Ryoko's hideout, conveniently labeled with Ryoko's name. Although the element of surprise was lost somewhat after Mihoshi rang the front doorbell, the team stormed the place, only to discover Ryoko trying to seduce Tenchi!
Angry at seeing her fiancé in a somewhat compromising position with Ryoko, Ayeka went on the offensive - by smashing everyone in sight with Ryoko's coffee table! Thanks to Ayeka's efforts, Ryoko was captured, but a sweep of her house revealed that the Ultra Energy Matter was nowhere to be found. Theorizing that Ryoko must have passed it on to someone else, Kiyone and Mihoshi looked through Ryoko's photo album- which indicated that the space pirate had a close relationship with Dr. Washu , the galaxy's number one mad scientist.
After a real world distraction while Washu manages to set the kitchen on fire, Mihoshi get back to her story. Desperate for information on Washu, Mihoshi decided to visit the now-captive Ryoko. When Ryoko refused to talk, Mihoshi tried to appeal to the space pirate's hidden good side. After a short while, Ryoko seemed to respond, and the ever-gullible Mihoshi decided to let the seemingly reformed and repentant space pirate free.
Naturally, Ryoko was far from reformed, and shortly after her release, she stole a shuttle and kidnapped Tenchi once again. After another round of unspecified hardships, the repentant Mihoshi and the team managed to locate Washu's fort. Unfortunately, infiltration of the fort did not get off to a good start- first Mihoshi led them to a giant roach motel, and then Sasami and Ryo-Ohki fell down a trap hole after Ryo-Ohki went after a plate of carrots!
Soon after, Mihoshi, Ayeka and Kiyone were captured by Washu and taken to her central chamber, where she proudly showed off her ultimate weapon
- the Galaxy Destroyer. Shaped like a giant head with two hammer-wielding arms, the Galaxy Destroyer had the power to smash through the very fabric of reality, destroying the universe itself.
Tenchi was also in big trouble- having been captured and tied up by Ryoko, it looked like he wouldn't be able to avoid being undressed and seduced by her! What with that and the Galaxy Destroyer, it seemed like things were at their worst. There was only one hope to save them- Sasami would have to transform into her magical girl alter ego, Pretty Sammy!
While Pretty Sammy rescued Tenchi from Ryoko's clutches, Washu set the Galaxy Destroyer in motion. As it began to smash away the universe, Kiyone couldn't help pointing out that Washu would be destroying herself as well, but in true mad scientist fashion, Washu was not too bothered about that.
Fortunately for everyone, Pretty Sammy teleported in just in time, and quickly freed the others from their restraints. Determined not to be thwarted, Washu sent a squadron of chibi mecha-Ryokos to attack, but the ever-resourceful Sammy used her magic to overwrite their aggression with love.
While the mecha-Ryoko's chased after Tenchi (their new love interest), Mihoshi, Kiyone and Sammy went after Washu, only to find that they were separated from her by a chasm filled with powerful energy. Using a long range Baton Flash attack, Sammy quickly knocked the Galaxy Destroyer's remote control out of Washu's hand. Quick to retrieve the remote, Kiyone turned to arrest Washu, only to fall into the energy chasm when the overeager Mihoshi slipped on a banana peel and knocked into her from behind.
Kiyone's fall into the energy triggered an overload, and everyone was quick to flee before Washu and her fortress were completely destroyed. Looking back from the safety of their ship, Mihoshi and the others acknowledged Kiyone's brave sacrifice, and wondered at the true identity of their timely savior Pretty Sammy...
Back in the present, Mihoshi's tale has sent everyone to sleep, with only Ryo-Ohki still listening avidly. Once again, Mihoshi pays tribute to the courageous actions of her former partner, completely unaware that Kiyone is still very much alive. Stranded in the wreckage of Washu's fortress, Kiyone has only one thought in her mind - to get revenge on the incompetent Mihoshi!