From Renta!:

In the third district of a certain town, there are only male cats. Rikuo, a smaller cat, has been the alpha leader of the turf for a long time. Even though most of the cats have left the third district as they got older, Rikuo's been a very reliable leader who's protected the area from invading cats. Toraji, a cat that Rikuo found abandoned as a kitten, has challenged Rikuo for the alpha leader's position. Will Toraji, who just turned into an adult, be able to get Rikuo on his knees...? Another story included is about Kuro, who has a serious problem as a male cat, and Ao, a house cat who knows nothing about his own physical needs and issues.