Episode 8 of "Hoshikuzu Telepath" focuses on Umika and her friends developing a prototype bottle rocket. The episode begins with the group collecting launch data for their prototype. Their teacher, fascinated by the unusual equipment, asks them questions. Haruno and Yu explain the use of eggs for their tests and mention that Matataki broke eggs out of frustration over failed attempts. The teacher advises them to stop Matataki from breaking any more eggs.

In a classroom discussion, Haruno notes that Matataki is working harder than usual. Matataki expresses her determination to win the championship, motivated by their shared dream of traveling to space. Haruno shares her perspective on the importance of their journey to the championship, valuing both the progress and the potential victory.

Later, the team gathers in the classroom to eat sponge cake, which inspires Matataki with a new idea for the rocket design. She delegates tasks to the others and, after further testing, presents a revised rocket design. Umika is relieved they managed to finish before the competition. As summer vacation begins, the team devotes more time to their rocket, leading to a disagreement between Matataki and Umika over a construction flaw.

Yu intervenes when Matataki's criticism becomes harsh, prompting Umika to leave the room. Yu follows to comfort her, and Umika soon returns to continue working. Meanwhile, Matataki reviews the construction documents and feels held back by the others. She stumbles upon Umika's rocket notebook and recognizes her dedication. Haruno reminds Matataki that the entire team is committed to winning.

Umika returns and promises to improve her rocket-building skills. Matataki clarifies that she doesn’t want to exclude anyone from the project but stresses the need for a basic understanding of the rocket's structure. She assigns Umika the task of leading the construction of the rocket's parachute.

On the day of the competition, the girls submit their rocket for inspection and review the competition rules. Kei, a rival, jokes with Matataki and wishes the team good luck. The episode ends with the announcer declaring the start of the model rocket championship as the girls prepare with determination.