Cologne tells Ranma that she recently received a Chinese tonic for hair-growth, but has no one to test it on. Ranma takes it to Genma, who seems skeptical. He's tried dozens of hair tonics in the past and none ever helped. Genma agrees to try this one though, and at dinner he tells the family that this too is a failure. Depressed, Genma decides to go to bed early, but not before Ranma pesters him about getting his hopes up over nothing. Genma flies into a rage, and suddenly towering stalks of spikey black hair shoot forth.
Whilst out waling through the streets of Furinkan, Ranma runs into Cologne who tells him she needs his father's help. Cologne explains a Chinese Pharmacist who eats at the Cat Café asked to test a new drug, but nobody at the Cat Café can use it.
When he returns to the Tendo Dojo, Ranma reveals the new drug (a hair growth tonic) to his father, but Genma is insulted at the idea of using it. Ranma is confused by this response and asks Genma if he doesn't want to grow his hair back. Genma states vanity is a difficultly that a true Martial Artist must overcome if he's ever to become and master, he then continues by saying that useless attempts to alter fate are a waste of time which could be better used for training, but Ranma boils down Genma's speech to him simply giving up after trying so many other hair tonics which failed.
Ranma then decides that he'll return the hair tonic then, but Genma grabs him by the shirt and tells him not to be so hasty. A little while later, while Genma is on his own, he takes the hair tonic and decides that trying a little can't hurt. However, at dinner, Genma reveals that he hasn't grown one new hair and decides that the tonic must not work after all. Kasumi is sorry for Genma, although Nabiki and Ranma are less sympathetic given their lack of empathy with Genma.
Hearing the unsympathetic comments hurts Genma, who decides to take an early night. However, Ranma follows him and begins to comment of how having the tonic not work really upset him. Initially Genma claims that it doesn't bother him at all, but with more pestering from Ranma he reveals that it did bother him after all. Genma then begins to tire of Ranma and begins to attack him, Ranma dodges the attack, but is shocked when suddenly a full head of spiked-black hair shoots forth.
As the Tendos look on in amazement at Genma's sudden hair growth, Ranma hits Genma with a hammer to see if the hair is real. Ranma is then quickly attacked by Genma's hair for hurting him. As Genma cries tears of joy at finally getting hair again, Ranma tells him he has too much and takes out a pair of scissors to try and even it out a little. Genma, however, isn't having a single hair cut and fends off Ranma with his hair, he then begins to laugh with joy when suddenly all of his hair falls out.
Later that evening, Genma retires to his bed where he begins to sob at losing his hair yet again. Ranma tries to cheer up his father, but just makes him annoyed again. Suddenly Genma's hair shouts forth yet again, causing Genma to realise that his hair grows because of his anger. Ranma then pulls a funny face at Genma and as he laughs at this sight, his hair falls out again, confirming what Ranma suspected to being what makes Genma's hair fall out last time. After Genma hits Ranma for making him lose his hair again, Ranma notes that the tonic bottom is only a sample and there isn't much left, to which adds that he'll have to use it very carefully.
As Genma sleeps, Ranma looks on and notes the similarity between Genma's hair and a Hedgehog. Just then Ranma hears Genma talking to him in his sleep, as well at crying tears of joy at having hair again. Ranma is initially touched by his father's actions, but gets annoyed with him when Genma roles in his sleep and stabs him in the back with his hair. In retaliation, Ranma punches his father awake and, after hearing what he'd done, Genma bows down to Ranma in apology (scratching Ranma's face with his hair in the process). Ranma then attempts to wake his father up, but to no avail.
While the Tendos get on with their usual morning routines, a loud scream from Genma echoes across the whole Tendo Dojo. As Genma chases after his son, he demands Ranma return the hair tonic bottle, although Ranma refuses as at this rate his (Genma's) hair is going to kill him. Craftily, Genma pours some oil under Ranma's feet so he slips and gives Genma the opportunity to reclaim his hair tonic bottle.
Genma quickly uses the tonic to regrow his hair and he and Ranma begin to brawl with each other. However, before either realise it they both end up above the Koi pond and subsequently fall in. Soun and Akane rush over to see what's happening, but are left speechless as Genma remerges from the pond as a giant panda-colored fur ball. Genma then roles out of the Koi pond and begins to chase Ranma through the streets of Furinkan.
After Genma has rolled over a couple of Furinkan High School students, Ranma decides she has to stop her father before somebody gets seriously hurt. Ranma then notices a mirror on the floor which had fallen from a student satchel. Planning to make Genma laugh at the sight of himself so all his hair will fall out, and sure enough Genma laughs at his own reflection and all his hair falls out (although Ranma still gets crushed into a nearby lamppost by the fur ball Genma). As Ranma informs Genma that he's used the last of the sample bottle, Cologne happens to come across the scene and decides to tell her friend not to make any more of the hair tonic.
Back at the Tendo Dojo, Akane tells Genma not to feel bad as his hair looked funny away, to which Ranma adds he doesn't need hair since he's an old man. Genma then shouts at his son, demanding he show some more respect, meanwhile, Soun reminds Genma that getting angry won't make his hair grow any more.
Cast in Order of Appearance
- Ranma Saotome (male)
- Genma Saotome (human)
- Kasumi Tendo
- Nabiki Tendo
- Soun Tendo
- Akane Tendo
- Genma Saotome (panda)
- Ranma Saotome (female)
To be added
To be added