Natsusa Yuzuki’s rugby career ended after a serious accident while riding on the back of Ibuki Ueoka’s motorcycle, when they were struck by a car. The crash left Natsusa with severe injuries, including a hernia, implied to be cervical radiculopathy which prevented him from continuing as an athlete.

Six months later, Natsusa returned to Doshisha University. His absence forced him to repeat a year, placing him in the same academic year as Yuu Mashiro and Yasunari Tsuru. Unable to play rugby, he decided to remain involved with the team by becoming a manager, much to the concern of Seiichirou Shingyouji, who worried about the strain on his health. At first, Natsusa struggled with his new responsibilities, frequently making mistakes such as forgetting to wash bottles, neglecting to shake sand from towels before laundering them, or diluting the sports drinks later revealed to be a habit carried over from Ibuki’s personal preference.

During practice, Natsusa witnessed Yuu collapsing from a gastric ulcer brought on by stress. Deeply concerned, Natsusa questioned Yuu about his passion for rugby. When Yuu confirmed his love for the sport, Natsusa invited him to join as one of the team’s managers, strengthening their bond and support for the team.

Natsusa Yuzuki is depicted with short orange hair that fades into a peach tone at the tips, vibrant green eyes, and delicate facial features. Before his accident, he maintained a muscular physique as a rugby player; however, following his injuries and long recovery, he lost much of his build and now has a noticeably slimmer frame.

His casual attire typically includes a white hoodie featuring a pair of green cat eyes, paired with blue pants and black boots.

Natsusa Yuzuki’s life revolves around his love for rugby. Although his accident prevents him from playing, he remains determined to contribute to the team by becoming a manager. He openly acknowledges that his new role may appear less impressive, but he accepts it as a sign of his devotion to the sport, placing rugby above his own pride. His popularity within the team reflects this commitment; when he suffered a relapse in his recovery, his teammates promptly visited him to show their support.

Natsusa also possesses a mischievous, occasionally sadistic side to his personality. While he rarely bullies others, he directs much of his playful teasing and sharp remarks at Ibuki Ueoka, often going to extremes in his banter with him. He has a talent for flattering seniors with well-placed phrases such as “Huh? Really?!” or “I learned a lot from you!”—comments that often win them over under the impression that he admires them.

His dynamic with his childhood friend Seiichirou Shingyouji further highlights his personality. Arguments between the two are common, with Seiichirou’s calm and pacifistic nature frustrating Natsusa, who grows increasingly annoyed when his jabs fail to provoke a reaction. These quarrels typically drag on, underscoring the contrast in their temperaments.

Ibuki Ueoka
Ibuki is closely tied to Natsusa, as it was while riding on his motorcycle that the accident occurred, ending Natsusa’s rugby career. Despite this painful history, their relationship is complex rather than hostile. Natsusa often directs his teasing and mischievous behavior at Ibuki, sometimes to the point of bullying, but beneath this dynamic is a deep trust. Ibuki is also one of the few people with whom Natsusa openly reveals his vulnerabilities.

Seiichirou Shingyouji
Seiichirou is Natsusa’s childhood friend. Their personalities frequently clash, with Natsusa becoming exasperated by Seiichirou’s calm and pacifistic responses during arguments. Despite their constant bickering, the two share a long-standing bond, and Seiichirou’s patience often balances Natsusa’s more fiery temperament.

Yuu Mashiro
Yuu Mashiro becomes close to Natsusa after collapsing during practice due to stress-induced illness. Concerned for him, Natsusa encouraged Yuu to consider his true feelings toward rugby and later invited him to become a manager. This gesture reflects Natsusa’s protective nature and his desire to help others remain connected to the sport he loves.

Yasunari Tsuru
As a fellow student placed in the same year after Natsusa repeated due to his accident, Yasunari represents part of Natsusa’s new peer group. Their relationship develops through their shared connection to the rugby team, though Yasunari initially struggles with fitting in compared to the more outgoing Natsusa.

The given name Natsusa (夏紗) is composed of natsu (夏), meaning “summer,” and sa (紗), meaning “thread” or “silk.” His surname, Yuzuki (柚木), combines yuzu (柚), referring to “grapefruit,” “pomelo,” or “citrus fruit,” and ki (木), meaning “tree” or “wood.” Together, his full name can be interpreted as “silken thread of summer” or “citrus tree of summer.”