TV-Series
Description
Yukari Tenkawa is a classmate of Takagi and Nishikata and a close friend of Mina Hibino and Sanae Tsukimoto. She is a female student initially around 12-13 years old, with long brown hair typically tied into a high ponytail, brown eyes, and glasses. She is the tallest among her group of friends. Her surname Tenkawa means "heaven/heavenly, sky, imperial" and "river, stream."

Generally quiet and reserved, Yukari exhibits a strong interest in romantic topics, particularly enjoying discussions about the relationship between Takagi and Nishikata, an interest that persists into adulthood. Despite her quiet demeanor, she often acts as a responsible figure within her friend group, reprimanding Mina and Sanae for their antics and academic laziness. She takes her studies seriously, consistently completing homework on time and striving for good grades, though she remains an average student academically. She is not athletic and cannot swim, requiring floatation devices in water. Her hobbies include reading manga, watching television, and eating sweets. She is also a picky eater and sensitive to cold temperatures.

As the class representative, she demonstrates a sense of duty, sometimes allowing classmates to copy her answers to prevent failure. Her relationships with Mina and Sanae are central, characterized by deep friendship but also frequent annoyance due to their behavior. She often scolds them for not studying or for teasing her but consistently helps them with their schoolwork. She is on friendly terms with Takagi, though their interactions increase significantly in their adult years.

In the spin-off manga "Ashita wa Doyōbi," which focuses on her and her friends' activities, more of her personality is explored. As an adult, she works as an office worker. She eventually becomes engaged but experiences pre-wedding anxiety, leading to a conversation with Takagi, who offers comfort and advice. Her friends Mina and Sanae remain a constant presence in her life, and they even continue their habit of observing others, such as tailing Takagi and her family to understand family dynamics. Her wedding is attended by Takagi, Nishikata, and their daughter, Chi. An incident notes that Chi was initially scared of her due to her pointed eyes but overcame that fear upon learning Yukari was to be a bride.

Her character development shows a progression from a middle school student fascinated by romance to an adult achieving her goal of marriage. While her core personality traits of responsibility and interest in love remain, she matures and faces adult challenges like pre-wedding nerves, supported by her long-time friends.