One
morning, Tenchi is sorting through some old clothes when he comes across
a yukata (a cotton robe similar to a kimono) that belonged to
his late mother. He leaves the garment out to air, and later that day
he finds Ryoko in his room trying it on. When he tells Ryoko that she
looks good in it, she dances with joy. However, the sleeve catches on
a door handle as she dances and rips clean off. As if this weren't bad
enough, Ryoko pulls the other sleeve off to match, and Tenchi yells
at her. Unfortunately, Ryo-ohki bounds in through the door at exactly
the wrong moment, and thinks that Tenchi is shouting at her. Heartbroken,
Ryo-ohki runs and hides in Washu's lab, where she is watched by a group
of strange brown creatures in a specimen tank.
Later
that day, Tenchi finds Ryo-ohki sulking out in the fields, and apologises
to her. With a little bribery (carrots, naturally), Ryo-ohki forgives
Tenchi, and the two head home, Ryo-ohki helping Tenchi to carry back
the carrot harvest. When they arrive back, Ryoko meets them at the front
gate. She has done her best to repair the damage to the yukata, and
Tenchi is ready to forgive her as well. Life returns to normal in the
Masaki home, but Ryo-ohki is still feeling a little melancholy when
Tenchi leaves her behind to go to work the next day.
Meanwhile,
in Washu's laboratory, the brown creatures seen earlier are restless.
They begin to form into a new shape - a humanoid female - and break
out of their tank. Nobody hears the escape alarm because they are watching
television. When Washu later discovers their escape, she summons the
girls to her lab. In the style of a school science lesson (with some
rather disruptive pupils), she explains that the creatures are The Mass,
a powerful polymorphic species that was used to form Ryoko and Ryo-ohki.
As they have escaped, she deduces that they are acting under the will
of an outside force, and quickly works out that it is Ryo-ohki that
caused them to break out of the lab. 
A
quick mind scan determines that Ryo-ohki's strongest desire is to help
Tenchi, meaning that The Mass must be headed out to the fields where
Tenchi is working, and he could be in danger. Ryoko rushes to leave
through the roof of Washu's lab, but falls foul of Washu's force field
and gets zapped.
Out in the fields,
Tenchi is startled by the appearance of the humanoid Mass, and hides
in the bushes. When the figure picks up his hoe and starts helping with
the crops, he assumes that it is friendly. However, when the girls arrive,
the Mass turns hostile and readies itself to attack Tenchi. Told that
any movement will aggravate it further, Tenchi freezes on the spot.
Ryoko, who has just recovered from her encounter with Washu's force
field, arrives on the scene and proves enough of a distraction for Ryo-ohki
to leap onto the the Mass' head and assimilate with it. The resulting
hybrid creature is Ryo-ohki's newest form, at first an adult female,
and later a child with big ears and fur. She even gains a limited capacity
for speech (her first word, quite appropriately, is "carrot").
