Ryoga Hibiki
Names: Ryoga Hibiki; Hibiki Ryoga; P-Chan (in pig form); "Eternally Lost Boy"
Name Meaning: Ryoga = "good fang"; Ryoga = "sound; noise"
Age: 16
Relatives: Yoiko (sister)
Nationality: Japanese
Eye Color: Blue
Hair Color: Black
Curse: Changes into a small black pig whenever he touches cold water, and he changes back to himself when he touches warm water
Love Interest: Akane
Loved by: Akari
Occupation: Wanderer; pet
Hobbies: Martial Arts, wandering, being P-chan for Akane
Fighting Styles: Unique style blending strength and unique weapons
Weapons: Umbrella, bandanas, and his belt
Weaknesses: No sense of direction; extremely gullible; cold water
Opponents and Rivals: Ranma, Mousse, Kuno
Ryoga is probably one of the characters who suffers the most in Ranma 1/2. He rivals with Ranma, but also has a grudging respect for him as well, despite all of Ranma's jokes about his other name being P-Chan, among other things. Ryoga seems to have a better understanding of love than Ranma, but it is a love which is unrequited and at the same time highly idealistic (he has been known to fantasize about situations in which he wins Akane). He also has a high sense of honor, though he is forever looking for a way to get Ranma out of the picture - he holds to the code of martial arts while at the same time still being a fairly good person. Willing to defend who he cares about, he is quick to anger against anyone who threatens the weak. Ryoga could be said to be one of the "tragic heros" of the story, always suffering, but able to keep plugging away in the midst of angst. His situation in the storyline makes him susceptible to bouts of depression and indecision on what he should do.
Ryoga Hibiki is considered Ranma Saotome's first serious rival to appear in terms of martial arts skill. Ryoga's grudge with Ranma goes back to when Ranma and Ryoga attended the same junior high (before Ranma's curse). Every day in the cafeteria, lunch was considered a war (it being a boys' school). Ryoga seemed to always be in reach of the very last Bread of the Day, but Ranma always just beat him out to it.
After weeks of this "dishonor", Ryoga challenged Ranma to a duel in the empty lot next door to his house. Unfortunately, Ryoga had, and still has, the worst sense of direction in the world, and wandered Japan for 4 days and 3 nights looking for the appointed place. Ranma waited for 3 days, and then left with his father on a traning trip to China. When Ryoga finally arrived on the 4th day, he found that Ranma had left, inciting his anger. Cursing Ranma as a 
coward, Ryoga immediately followed after Ranma, but with his horrible sense of direction he couldn't catch up with him, being always one step behind.
Then one day, Ryoga finally caught up to Ranma (though he didn't know it at the time). It so happened he wandered to Jusenkyo, the Ground of Accursed Springs, where falling into any of the springs turns you into the form of the person or animal that drowned there before. As Ryoga stood on a cliff overlooking the springs, a panda almost bowled him over the edge. Ryoga leaped out of the day, only to be knocked into a spring by a certain red-haired girl. (If you didn't guess already, it was Genma and Ranma who were responsible for cursing Ryoga)
Ryoga was knocked into Heituenniichuan, the Spring of Drowned Black Piglet. Now whenever Ryoga is splashed with cold water, he turns into a little black piglet.
Ryoga eventually made his way to Ranma's high school and challenged him. Though their first real fight ended in a draw (with Akane losing her long hair to one of Ryouga's stray weapons) Ryoga continued to challenge Ranma periodically, even going so far as to challenge him to a duel in the middle of the night once. It was around this time that Ranma and Ryoga found out about each other's curses...which made Ryoga even more angry (as he found out that Ranma was directly responsible for his curse). A lot of his anger changed, however, when he was cared for while in his cursed form by Akane, who was unaware (and still is) that the little black pig she was taking care of was really the cursed Ryoga.
Up to this time, Ryoga had thought there was absolutely no advantage to being a pig. He had gotten into various situations as a pig (he was almost eaten once, by Genma), and hated his curse. But when Akane took him in his cursed form as a pet (who she named "P-chan" - "P"
for pig and "chan" for little/cute), Ryoga finally realized there was actually someone out there who liked his pig form. As a result, he fell in love with Akane, even though to this day, Akane still doesn't know that her new pet "P-Chan" and Ryoga are the same person. Ryoga loves her secretly, without telling her his true feelings, fearing her reaction.
Thus, Ryoga either wanders in and out of the Tendo household as P-Chan, or challenges Ranma in his human form - always looking for a window of opportunity to seize to get Akane away from Ranma and over to him. It seems to be unlikely for Ryoga to win in this battle, however, because Ryoga knows in his heart that Akane actually loves Ranma, and not him. The pain is almost unbearable to him, but his hope keeps him going. Later, a girl named Akari happens to fall in love with him, and Ryoga has to decide on which one will have his heart...