If you enjoyed the first Kitty Corner book, Callie, you'll enjoy Otis; it's more of the same, really. The only significant difference between Callie andOtis--other than featuring different kittens, of course--is that the protagonist of the former is Mia Battelli, while her brother Michael takes the stage in this installment.
After the events of Callie, the Battelli family is open to the idea of fostering more kittens in the future... but not quite as open as the end of the first book led the reader to believe, apparently, as Mrs. Battelli continues to be very resistant to the idea of allowing domestic animals into her apartment. But Callie's influence has led Michael to develop a newfound love of cats, so when he finds an abandoned kitten that his friend won't be able to foster or adopt, Otis the tabby comes home with him.
Essentially, the story has all the same elements as the previous installment. One of the Battellis find a kitten and, in spite of the mother's grumpiness, they care for it while they search for a "forever home"; another character shows interest in the cat, but doesn't take it right away. Meanwhile, the cat shows off an annoying habit--Callie's was escape attempts, and Otis' is yowling--that exacerbates the search for a permanent home. Finally, the earlier character agrees to take the cat off the Battelli's hands, and everyone lives happily ever after. (On a similar note, the weirdness involving the inclusion of the cat's POV continues... and I really wish it wouldn't.)
In any case, I'll definitely be reading the next two Kitty Corner books soon, then eventually moving on to Puppy Place. I hope to see the next book shake things up a bit, but so far, they're perfectly acceptable books for young animal lovers and a great way to introduce children to the concept of fostering pets.