Asuna Kangoshi works as a nurse at Yū Mental Clinic alongside psychologist Ryō Shinnai. She is the youngest daughter of the Kangoshi family, with two older sisters, Iyashi and Himeru Kangoshi, who are also nurses at the clinic. Her grandfather, Sukizō Kangoshi, occasionally appears.

Asuna possesses light blue eyes and distinctive purple hair, usually styled in a long side ponytail. She wears a standard nurse uniform during her clinical duties.

She radiates cheerful and energetic energy, though moments of denseness or naivety surface. This trait leads her to frequently misinterpret the names of psychological disorders or medical terms. These misinterpretations create comedic misunderstandings requiring correction during discussions about mental health topics.

Her primary role involves assisting in patient consultations and educational discussions on psychological conditions. She actively participates in explaining mental health concepts, often through comedic banter or lighthearted exchanges with Ryō Shinnai. Her interactions introduce viewers to topics like depression, panic disorders, sleep disorders, and other psychosomatic conditions covered in the series.

The surname "Kangoshi" phonetically resembles the Japanese word for "nurse" (看護師), though written with different kanji characters (官越), reflecting her profession narratively.