Back at school, Umaru's rival Sylphynford Tachibana challenges her to a tennis match to prove her superiority. While Umaru tries to maintain her "perfect girl" image, she is eventually exhausted by Sylphynford's relentless energy and Kirie’s surprisingly intense skills.

This episode is notable for introducing two characters who become central to the series:

Taihei's high school friend and coworker (and Kirie's older brother) makes his first appearance. Pop Culture References & Trivia

The "6 types of Miku" prize scene references a popular internet meme from Pixiv. Where to Watch

Taihei's colleague and Sylphynford's older brother. He is an otaku who unintentionally causes his sister’s tournament exit.

The series is famous for its parodies, and Episode 4 is packed with them:

Umaru uses a cat ornament in a parody of Pokémon . During the tennis match, a daydream sequence references the "Tezuka Zone" from Prince of Tennis .

The arcade "PLAZA GAPCOM" refers to Plaza Capcom . Space Stream Fighter IV is a clear nod to Street Fighter IV , featuring a Ryu-lookalike employee and a Guile-like character on screen.