Densuke

Densuke is a sickly teenage boy who is on the brink of death because he refused to take his medicine from the very ugly nurses at the Hospital. Despite his innocent and ill appearance, he is actually an extremely perverted, flirtatious, butt rubbing, filthy lecher who would rather die than be touched by a hideous woman.

History
Little is known about Densuke's past, however, he is known to have been in hospital for a long time and refuses to take any medication (citing pharmacophobia (fear of taking medication) as the cause) unless a pretty nurse told him to.

Densuke
Densuke is lying in his hospital bed looking out at the Apple tree, when Ranma (in his female form) appears and begins to take the apples. Limply Densuke throws a stool at Ranma and is kicked in the face by Ranma as a result. His mother then rushes in and dries to make it so he'll die in his mother's arms, but Densuke refuses and goes to Ranma and asks her for her help.

Suddenly Densuke collapses onto Ranma and mutters that at least he'll be able to die in a pretty girl's arms. Despite this sentiment, Densuke uses this chance to squeeze Ranma's chest and then sent flying by Ranma.

After Ranma learns of Densuke's problem with taking medication, she agrees to pretend to be a nurse so as Densuke will take it. Unfortunately, Densuke adds that Ranma has to put it in her mouth and kiss him. Ranma ends up pinching Densuke's nose so as he'll have to open his mouth or he'll suffocate. This doesn't work and Densuke does nearly suffocate to death.

Once he's resuscitated, Densuke reveals that he's never gone out with a girl and perhaps if he experience the joys of youth it would give him a reason to live. After Ranma reluctantly agrees, Densuke makes her put on a school uniform outfit. However, when Ranma realises this she kicks him for this perversion.

Ranma and Densuke then go out of a "date", during this time they visit several places where Ranma tries to trick Densuke into taking his medicine. Densuke, however, manages to prevent this from happening at every turn. At their final dating spot, Densuke puts sleeping powder in Ranma's drink and tries to have his way with her when she awakens, but is just sent flying again.

Back on the date and Densuke finally agrees to take his medicine as when he's with Ranma he wants to be alive. Despite this, he stills wants Ranma to kiss him in order to take the medicine. This angers Ranma who goes to punch Densuke, but Densuke collapses before she makes contact so Densuke is quickly returned to hospital.

Densuke's Doctor gives him a very poor outcome should he not take his medication now and Ranma is left in a bind about how to make Densuke take it. Densuke comes round the next morning, feeling better that he has done for a long time, and finds Ranma asleep next to his bed. Desnuke decides that Ranma must've given him the medicine mouth-to-mouth and decides to thank her with a kiss.

Unfortunately for Densuke, Ranma wakes up and punches him and several other items into the air. After Ranma lies that it was her who gave Densuke the medicine (it was actually his Doctor), the flask of hot water which Ranma had sent into the air earlier lands on her and changes Ranma back into his male form.

With his curse revealed, Ranma explains he'd hoped to leave before Densuke found out but it doesn't matter since he's healthy again. Densuke retorts by calling Ranma a pervert which angers Ranma so he sends Densuke flying yet again asking who he's calling a pervert.

Two weeks pass and Densuke is finally well enough to leave the hospital. Densuke also continually tells himself that it was OK since Ranma was a girl at the time (or so he believes).

Trivia

 * Densuke, as well as liking women in nurses uniforms, is also an ephebophile (more commonly referred to as having a Lolita-complex), as shown when he wants Ranma to dress in a rather school uniform-esque outfit.
 * His personality and tendencies are very similar to Miroku the lecherous monk, a character from Rumiko Takahashi's other series InuYasha.

Quotes

 * If only I could experience the joys of youth, it would give me a reason to live. - Densuke before he manages to get Ranma to dress in a school uniform-esque outfit.