As you explore, you'll encounter numerous animals that will give you certain tasks. One of them is the "Boss Cat vs. Ramune!" task, and you'll need to catch Ramune, the bird in Little Kitty, Big City, to complete this task.
How to do Boss Cat vs Ramune in Little Kitty, Big City
Catching this yellow bird won’t be easy, though, and you’ll need to use a few tricks to do so. Here’s everything you need to know before you start catching this infamous bird in Little Kitty, Big City.
As you explore, you will find a shop in the southeast corner of the map. As soon as you enter, you will see a black cat kneading a human's back to comfort him. When you interact with this cat, you will learn that his sister has escaped from the cage and will not return until she fights a boss cat.
Since you're offering to help, you'll need to catch Ramune, the bird in Little Kitty, Big City. She's masquerading as Gecku so she can go back to her cage. Finding Ramune is incredibly easy, because as soon as you come out of the store, you'll quickly see her flying by the building across the street.