Mayumi Doujima promises her parents that she will give up on her dreams of becoming an astronaut on her 14th birthday if she cannot find a star she once saw long ago. Overhearing her troubles, the eccentric Manabu Soutouin offers to help her search for the star alongside the rest of Yubiwa Academy's mysterious Pretty Boy Detective Club, whose rules are as follows: Be pretty, be a boy, and be a detective! However, Mayumi is unique—she can see many things that ordinary people cannot. Her eyesight allows her to see the tiniest of details, from people approaching her at a distance to hidden traps that would otherwise go undetected. When the search for the lost star begins to sour, the Pretty Boy Detective Club end up entangled in something far beyond what they ever imagined.

On the first day of junior high school, Mato Kuroi happens to run into Yomi Takanashi, a shy, withdrawn girl whom she immediately takes an interest in. Mato tries her best to make conversation with Yomi, wanting to befriend her. At first, she is avoided, but the ice breaks when Yomi happens to notice a decorative blue bird attached to Mato's phone, which is from the book Li'l Birds At Play. Discovering they have a common interest, the two form a strong friendship. In an alternate universe, the young girls exist as parallel beings, Mato as Black★Rock Shooter, and Yomi as Dead Master. Somehow, what happens in one world seems to have an effect on the other, and unaware of this fact, the girls unknowingly become entangled by the threads of fate.

Wishing to be independent, 16-year-old Maika Sakuranomiya is desperate to nail down a part-time job so that she can afford to study abroad. Unfortunately, her applications are constantly rejected due to the menacing look she unintentionally makes whenever she smiles, despite her otherwise cheerful disposition. After yet another failed interview, she chances upon Café Stile, a coffee shop where the servers interact with the customers while roleplaying distinctive characteristics. The Italian store manager, Dino, becomes infatuated with Maika's cuteness at first sight, and offers her a job as a waitress with a sadistic nature. Coupled with her inherent clumsiness, she successfully manages to serve a pair of masochistic customers in accordance with her new, ruthless persona. Alongside Kaho Hinata as the tsundere and Mafuyu Hoshikawa as the younger sister, Maika decides to make the most out of her unique quirk and cements her position in the cafe with merciless cruelty!

Having escaped the many horrors of her village, Saya Kisaragi vows to hunt down the monster responsible and make him pay with his life. As she tears through flesh and bone for her vendetta, she encounters SIRRUT, a group of ingenious hackers, who enlist Saya to help them defeat a common enemy—someone she knows all too well. Unfortunately, the path she follows is paved with tragedy, as once again, Saya faces betrayal at the hands of those she has come to trust. With her back against the wall, the fearsome monster slayer must fight with all her strength and skill if she is to overcome this final mission and exact vengeance.