"BanG Dream!: Asonjatta!" is a short anime series that serves as a comedic spin-off of the main "BanG Dream!" franchise. The story revolves around the members of Poppin'Party, a high school girl band, as they navigate humorous and exaggerated situations in their daily lives. The series adopts a chibi-style animation, emphasizing lighthearted and slapstick comedy over the more serious and dramatic tones of the main series.

The narrative is episodic, with each episode presenting a self-contained scenario that highlights the quirky personalities of the band members. Kasumi Toyama, the energetic and optimistic lead vocalist and guitarist, often finds herself at the center of these antics, whether she’s trying to come up with new song ideas or getting into misunderstandings with her friends. Arisa Ichigaya, the pragmatic and level-headed keyboardist, frequently acts as the voice of reason but is not immune to the chaos. Tae Hanazono, the laid-back and enigmatic guitarist, adds to the humor with her unpredictable behavior and deadpan reactions. Rimi Ushigome, the shy and kind bassist, often finds herself caught up in the group’s schemes, while Sāya Yamabuki, the dependable drummer, tries to keep everyone grounded despite her own occasional missteps.

The humor in "Asonjatta!" derives from the exaggerated interactions between the characters, their over-the-top reactions to mundane situations, and the absurdity of their adventures. For example, one episode might feature the group attempting to write a new song but getting sidetracked by a series of ridiculous events, while another might focus on their attempts to solve a trivial problem that spirals out of control. The series maintains a playful tone throughout, with no overarching plot or significant character development, instead focusing on delivering quick, entertaining vignettes.

The supporting cast, including members of other bands from the "BanG Dream!" universe, occasionally appear, adding variety to the comedic scenarios. However, the primary focus remains on Poppin'Party and their dynamic as a group of friends who share a passion for music, even if their antics often take precedence over their musical pursuits. The series is designed to appeal to fans of the franchise who enjoy seeing their favorite characters in a more relaxed and humorous context, offering a lighthearted contrast to the main series' emphasis on music performance and emotional storytelling.