Hana Shirosaki is an elementary school student and the only daughter of Haruka Shirosaki. Classmates and close friends with Hinata Hoshino, Hana possesses long black hair adorned with a pink flower clip on the left side—a gift from her grandmother—and bright blue eyes. Her typical attire is her school uniform: a long navy blue dress featuring a red bow, white sleeves, a navy blue striped collar, paired with white tights and brown shoes. She stands approximately 142 cm tall. Born on March 7th, she is a Pisces and the youngest within her friend group, which includes Hinata Hoshino, Noa Himesaka, Kanon Konomori, and Koyori Tanemura.

Hana exhibits a calm, mature, and often stoic demeanor, presenting herself in an adult-like manner. Despite this general reserve, she displays intense enthusiasm for sweets, particularly pudding, which easily soothes her when upset or angry. She harbors a strong fondness for the character "Higero," finding it cute despite others' disapproval, and dislikes ghosts while fearing dogs due to a belief a bite could be fatal. Her personality includes brutal honesty and deadpan snarking, positioning her as the only sane voice among her friends. She occasionally reveals a big eater tendency, especially regarding desserts.

Hana's story initiates when Hinata invites her home, leading to an immediate, awkward encounter where Hinata's older sister, Miyako Hoshino, becomes smitten, leaving Hana disturbed. Despite initial reluctance, Hana gradually warms to Miyako primarily through Miyako's persistent offers of homemade sweets in exchange for wearing cosplay outfits. This evolves into a mutual arrangement where Hana leverages Miyako's culinary skills to indulge her sweet tooth while tolerating the cosplay requests. Their interactions reveal Hana's deeper layers, including vulnerability, such as seeking physical comfort during a horror movie.

Her development marks a shift from viewing Miyako solely as a source of confections to acknowledging Miyako's earnest efforts in activities she cares about, like cosplay design and baking. By the series' conclusion, Hana explicitly expresses respect for Miyako's dedication, signifying a meaningful thaw in her initial icy demeanor. This growth extends to her broader social circle, where she participates in group activities like school festivals and cultural events, demonstrating increased openness and reliance on her friends. Her journey continues in the theatrical film "Precious Friends," further solidifying her bonds and showcasing her ongoing integration into the group dynamic.