The Cat Who Loves Fish Tails

On this planet, there are many Brain Cities, each ranked according to brain capacity. Ordinary Brains are the lowest rank, while Elite Brains, Leader Brains, and Divine Brains are higher ranks. To advance, one must expand their brain capacity and pay the corresponding fee.

The cost varies by rank. Expanding an Ordinary Brain costs ten thousand gold coins, an enormous sum for an ordinary person. To earn those ten thousand gold coins