Yotaro's mansion

Yotaro's Home is a luxuriant seaside mansion located somewhere in the more mountainous coastal regions of Japan. In the anime, it is depicted as being near a small village, but still isolated from it, which suits one of the occupants just fine. The mansion, as its name suggests, is most notable for being the home of Yotaro, a pampered, lazy, spoiled boy, and his poor, devoted, gentle-hearted widowed mother. Yotaro's mother is worried sick about Yotaro, because he will not leave the house and seems to display no interest at all in playing outside or making any friends. Yotaro is perfectly happy with spending the vast majority of his time in his bed, reading books and playing Super Nintendo, excusing his refusal to leave his room or even his bed as being a "frail constitution" or "weakness" - which is precisely why his mother is so worried, as she's certain that he would recover all of his strength if only he would spend some time outside in the sun.

As Ranma Saotome and, in the anime, Akane Tendo discover, though, there is absolutely nothing physically wrong with Yotaro at all; he is merely too lazy and too comfortable in his isolated little environment, and his mother so pampers and spoils him that she doesn't have the willpower to force him to go outside and play. The only ray of hope for Yotaro's mother is that Yotaro is obsessed with pandas; he dreams of owning a pet panda named "Kumahachi" and swears to his mother that if he had him, he would spend all day playing outside with him.

His mother thinks her prayers have been answered when she discovers a panda rooting around in her garbage cans one night, presenting him to Yotaro as Kumahachi. However, she is in for a great disappointment; her "lucky find" is none other than Genma Saotome, who got lost in a blizzard while searching for a private Christmas Tree for Happosai (in the anime) or wandered off to escape a training trip of Ranma's (in the manga). As lazy as Yotaro is, and gluttonous to boot, Genma is quite happy to join Yotaro in lounging around and playing video games, only moving to gorge himself on the finest, most expensive seafood that Yotaro's mother is willing to give him.

In the end, Yotaro's mother learns that there is nothing wrong with her son when Ranma finally gets so irritated with Genma's act that s/he grabs him and carries him away on her back, Yotaro chasing the Saotomes all the way back to the Tendo Dojo in his desperate attempt to get Kumahachi back.