Haiji has dark brown hair and matching dark brown eyes, giving him a composed and mature appearance. One of his most notable physical features is a long, jagged scar on his right knee, a reminder of his struggles and dedication to running.

He is frequently seen in a tracksuit, reflecting his athletic lifestyle and commitment to training. When relaxing at Chikuseisou, Haiji opts for a more casual look, often wearing a plain gray t-shirt paired with a green plaid hanten, adding to his approachable and warm demeanor around his teammates.

Haiji is known for his friendly and outgoing personality, which makes him a natural leader among his teammates at Chikuseisou. However, beneath his charming demeanor lies a subtly manipulative side. Haiji is deeply driven and unwavering in his pursuit of his dream to run in the Hakone Ekiden, and he is willing to go to great lengths to convince his housemates to share in his vision, even resorting to light-hearted threats or clever persuasion when necessary.

Despite his determined and sometimes relentless nature, Haiji genuinely cares for his teammates and their well-being. His concern is evident throughout the series, as he consistently encourages and supports them in their training and personal struggles. During the Hakone Ekiden, he goes out of his way to connect with each Kansei runner before their leg of the race, demonstrating his dedication to fostering unity and camaraderie within the team.

Haiji has been passionate about running from a young age, and his love for the sport drove him to dream of participating in the Hakone Ekiden. However, a knee injury temporarily derailed his athletic ambitions, forcing him to step back from competitive running. Undeterred, Haiji focused on building a team at Kansei University, recruiting the residents of Chikuseisou to join him in his quest.

His time at Chikuseisou shaped him into a leader who values camaraderie and perseverance. Haiji’s unwavering belief in his teammates and his ability to unite people from diverse backgrounds highlight his role as the heart of the series.

Haiji is the mastermind behind the revival of Kansei University’s track and field team. His vision of competing in the Hakone Ekiden inspires the residents of Chikuseisou, many of whom are inexperienced runners. Through his guidance, Haiji transforms a group of unmotivated students into a cohesive and determined team.

Haiji’s role as the team captain extends beyond strategy and training. His ability to empathize with and motivate his teammates ensures their steady progress. Despite his own physical limitations due to his knee injury, Haiji continues to lead by example, demonstrating resilience and passion.

Kakeru Kurahara
Haiji acts as a mentor and motivator for Kakeru, helping him rediscover his passion for running. Their dynamic reflects mutual respect, with Haiji’s optimism complementing Kakeru’s intensity.

Chikuseisou Residents
Haiji shares a unique bond with each resident, recognizing their individual strengths and weaknesses and fostering a sense of unity within the group.

Kansei University Track Team
Haiji’s vision and leadership are the driving forces behind the team’s success, earning him the admiration and loyalty of his teammates.

The name Haiji (灰二) carries the meaning of “ash” (灰, hai) and “two” (二, ji), which may symbolize resilience and transformation, akin to the renewal of life from ashes.

Haiji’s surname, Kiyose (清瀬), combines “clear, pure, clean” (清, kiyo) and “swift current, rapids” (瀬, se), evoking imagery of a clear and fast-flowing river, reflecting his pure determination and dynamic energy as a runner and leader.