Taikai ni Hibiku Call  

Call Echo in the Oceans, 大海に響くコール

Nakai Kawazu is a high school student who lacks specific interests or aspirations for the future. During one of her days, she visits an aquarium where she meets her classmate, Kanzaki, who is deeply passionate about killer whales. Kanzaki talks about how fascinating killer whales are, which piques Nakai's curiosity. She witnesses the killer whales performing for the first time and is struck by their impressive appearance.