Shizuku's wanted goldfish. Though Shizuku stated that she never liked goldfish, she felt disappointed when she never got one. This was because she had spent time reading about goldfish and knowing everything she would need to know. She wanted to know what it felt like to love something and to care for it.
When Shizuku was in primary school, she told her father that she wanted goldfish for the purpose of taking care of them. But her mother was busy, so she couldn't get the goldfish on the day of the fireworks. Though her father offered her to buy one anyway, she refused, saying that it was not needed.