Ryoko is fishing when Sasami and Mihoshi run up and ask her what she's doing. Just then her pole shakes and she pulls up Ryo-Ohki with a fish. The fish gets loose and Ryoko tells Ryo-Ohki that she'll get no carrots if she doesn't catch a fish.
Tenchi is changing out clothes for the change of seasons when he finds a dress that used to belong to his mother.
When Tenchi gets home he goes to his room to find Ryoko wearing the dress. He tells her she looks good in it and she twirls around the room. She snags the sleeve on the door handle and rips it off. In order to balance the effect, she rips off the other sleeve. Ryo-Ohki phases through the door just as Tenchi yells "I hate you" to Ryoko. Thinking that he's yelling at her, Ryo-Ohki runs (hops) from the room and Tenchi chases after trying to apologize.
Ryo-Ohki runs into Washu's lab and sits down in front of a glass tank holding glob-like creatures that float around in there. Washu comes up and asks what's wrong but Ryo-Ohki just runs off.
Tenchi finally finds Ryo-Ohki in the carrot fields and apologizes. They pick some carrots and head back home. On the way, Ryo-Ohki levitates Tenchi to make the walk back easier. When a car comes by, they fall and drop the carrots. Ryoko meets them at the gate with a poorly mended dress and Tenchi tells her he's not mad anymore.
The next morning Tenchi goes out to the fields and tells Ryo-Ohki to stay home, Ryo-Ohki goes back to the lab and is feeling down. She sits by the same tank and the glob-like creatures gather around again. Washu comes up and tells Ryo-Ohki that their name is Mass which means the original element of all things. They were used as Ryo-Ohki's life base. Ayeka comes in and tells them it is tea time. After they leave the Masses begin to merge together forming something.
The girls are eating and watching some alien soap opera as the Mass begins to take on a vaguely human female shape and breaks out of its container. The soap is interrupted by a news flash and the girls go their respective ways.
Tenchi is working in the field as the Masses are make their way towards him.
Washu storms out of her lab and calls the girls. She explains that the Masses have escaped. She reveals that it was the Masses mixed with her egg cells that created Ryoko and that a mineral life form was used for Ryo-Ohki. Ayeka asks what a Mass is and Washu begins school.
The Masses are a group creature that has a leader that they call the Brain. If they detect and will stronger than the Brain, then they accept it as their leader and follow it. The Masses are generally gentle creatures but they can become quite dangerous when exposed to tension. They are very powerful as they as composed of material, neutral material and anti-material. Blah blah blah...
They determine that Ryo-Ohki is the one that affected the Masses and they read her mind to determine what she was thinking in order to do so. They find that it was Ryo-Ohki's thoughts of helping Tenchi that drove the Masses to escape. The problem is that, if they discover the hidden power the Tenchi holds, they will attack him. Ryoko takes off but forgot about the shield around the lab. The rest of the group go to find Tenchi.
The Masses approach Tenchi in the field and he assumes that they are one of Washu's experiments. He moves out of the way as the Masses pick up the how and begin to dig in the field. The girls show up and yell for Tenchi to not move. Ryoko finally recovers and leaves the lab as Washu informs Ayeka, Mihoshi and Sasami that the decoy is on the way. Tenchi falls and the Masses energizes for a blow, when Ryoko arrives. Instead of blasting Tenchi, they blast Ryoko instead. Ryo-Ohki breaks free from Washu and jumps on the Masses. Washu commands Ryo-Ohki to "assimilate now and control" and the threat is over. When they look down at Ryo-Ohki, she has changed form.
The episode closes with a mysterious ship making its way through space.