Kyouko Nishina is the school nurse at Hasumidai Academy and the advisor to the gardening club. Her infirmary is well-equipped and notably comfortable, stocked with coffee sets and sweets. She possesses a straightforward and carefree personality, which results in a lenient approach to enforcing school rules. Her approachable nature and genuine attentiveness to student concerns have earned her a reputation as a popular confidante, though occasional rumors suggest she can be sensitive when in a bad mood.

She maintains a close friendship with her colleague, Yui Nonohara, and frequently asks Naoki Kuzumi to perform tasks for her. A minor ongoing conflict involves the astronomy club's observation dome; its telescope can be angled downward to view her infirmary, leading her to confront the club multiple times over accusations of peeping.

Physically, she is an adult woman with green eyes and orange hair that she usually wears tied up. She stands 167 cm tall, with measurements of 89 (D cup), 60, and 88 for her bust, waist, and hips. Her typical attire consists of a lab coat and a necklace.