After trying to escape from Haru after school, Yuki runs into a girl who has a different water pistol similar to the one Haru carries around. She squirts him with it anyways. Suddenly, the three of them are on the roof of a tall building, with the girl claiming to be Haru's sister, named Coco, who thanks Yuki for being Haru's friend. She then tells him that they are aliens who came to Earth to catch a certain fish with the fate of the world at stake, and Yuki decides to help catch that fish with the water pistol pointed at his face again.
Later, they get Natsuki to come out and fish with them again after pestering him at work. He shows them briefly how to make a Uni Knot for lure fishing. Yuki gets frustrated and thinks about quitting, but after seeing Haru's sister with her water pistol he tries to make it work anyways. Unfortunately, when he gets a bite, his line snaps off due to a shoddy knot. He finally gives up and goes home to bed. Haru tries to get Yuki out of his room, but Kate encourages him to leave Yuki alone for the night.
The next day, a frustrated Yuki goes over the scene in his mind until he finally gets the knot tied correctly. He then goes down to the beach where Haru is fishing with his sister and says he'll help them find their fish.
The day after that, Yuki goes up to Natsuki in school and shows his proof of a perfectly tied knot to him. Another transfer student joins their class, a 25 year old Indian man named Akira holding a duck in his arms. However, Haru seems afraid of him.