Jun Kitagawa occupies the desk behind his classmate and friend, Yuichi Aizawa. He possesses a cheerful, active personality, frequently providing comic relief through his romantic rejections by Kaori Misaka and Yuichi's sarcastic responses. Despite this, Jun demonstrates loyalty and genuine care as a friend.

He consistently harbors a crush on Kaori Misaka, often following her despite her dismissals. Jealousy occasionally surfaces, particularly directed at Yuichi, whom Jun perceives as more successful with girls. This dynamic contributes to his role in character development.

His background hints at a past romantic interest from Nayuki Minase during middle school. Jun contributes to significant plot events: spotting Shiori Misaka standing outside in the snow during school, initiating her introduction, and discovering Ayu Tsukimiya's lost item during the group search.

A pivotal moment occurs during Mai Kawasumi's story arc. Following an incident at a ballroom dance he helped organize, the student council president seeks Mai's expulsion. Jun falsely claims prior knowledge of Mai's actions to assume blame, preventing her expulsion despite the president's skepticism. This act underscores his willingness to protect friends at personal cost.

Physically, Jun has short, straight blonde hair reaching his eyes, featuring an ahoge (antenna-like hair), brown eyes, and a fair complexion. He primarily wears his school uniform but dons a jumpsuit during formal events like the ballroom dance or Shiori's birthday party. He stands 175 cm tall, weighs 61 kg, has blood type B, and his birthday is April 18.