"Sekai Saionji is a key character in the Japanese manga ""1/24 Romance"". She is a 16-year-old high school student who falls in love with her classmate Makoto Itou. Sekai is a supportive friend and is not afraid to speak her mind.

Sekai is first introduced as Makoto's classmate, and it is hinted that she has feelings for him. She is initially seen as a cheerful and energetic girl who is always looking for ways to help Makoto. As their relationship develops, Sekai becomes more and more devoted to Makoto.

Sekai's personality is complex and multifaceted. On one hand, she is a bubbly and cheerful person who is always trying to brighten up other people's days. On the other hand, she can be stubborn, headstrong, and quick to anger. This fiery temperament is often directed at Makoto, who she sees as indecisive and weak-willed.

Despite these flaws, Sekai is a genuinely caring person who is willing to go out of her way to help others. She is fiercely loyal to her friends and will stand up for them no matter the cost. This is particularly evident in her relationship with Makoto, where she encourages him to pursue his dreams and supports him through his struggles.

Sekai is also a complex character in terms of her own emotions. She struggles with her own feelings for Makoto, which are complicated by his own conflicting emotions. This leads to many tense moments between the two of them, as well as a few emotional outbursts.

Overall, Sekai Saionji is a well-rounded and complex character who adds depth and nuance to the story. Her devotion and loyalty to her friends, as well as her struggles with her own emotions, make her one of the most memorable characters in the manga."