Experimental Herb · Towering Hair (試薬・努髪天 Shiyaku・dohatsuten?) is the 315th chapter of the manga it is also the first and only chapter of the Hair Tonic Arc. 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.