Mikan Enikki (みかん・絵日記) is a manga series written and illustrated by Miwa Abiko. It was featured in Hakusensha's magazine LaLa from June 1988 to January 1995.
A TV anime (stylized みかん絵日記) loosely based on the manga was produced by Nippon Animation and ran from October 16, 1992, to June 18, 1993, on CBC Television, TBS and other JNN affiliates.
Plot
Tom, an orange cat, the protagonist of the story, had to leave his home after his owner had died due to illness. After wandering around for a while, he finally arrived at the Kusanagi family, where he was adopted and given a new name, Mikan, based on his orange fur (mikan is the Japanese word for "orange fruit"), but the Kusanagis soon found out that Mikan was no ordinary cat: he could speak human, and could walk on his hind limbs like a human. Shocked at first, the family gradually adopted a more welcoming attitude, and finally accepted the fun-loving cat as one of them. From then on, Mikan got on numerous adventures in the human world as a talking cat, which was kept secret by the Kusanagis. Mikan later got "married", had children, and one of them could also speak human like he did.
Apart from the typical slice-of-life stories, the manga also had some pure fantasy chapters, where Mikan and his gang, through various random means, got into different worlds of magic and dragons. These stories were never adapted for TV.
The TV anime adaptation had a similar premise, featured characters and some plot points from the manga (such as Mikan's backstory, a few relationships between characters, the short travel arc, etc.), but all of its story execution was entirely original.