Aizawa is still going strong in the manga. There's no event or storyline that has resulted in his death. The creators have chosen to keep him as an active character.
The ending point of the Tomo-chan anime in the manga can be a bit tricky to determine. Sometimes, the anime might condense or expand certain storylines compared to the manga. You might need to do a detailed comparison to figure it out precisely.
One common theme is his role as a teacher and mentor. Many fanfics explore how he guides and influences his students at UA. Another theme is his mysterious past. Writers often like to uncover bits of his history that are not fully shown in the original work. Also, his relationship with other characters, like his colleagues at UA, is a popular theme.
Aizawa Ryaka was described as a strong, quick-witted female character in " Hot Blood High School 1." Although she has always been seen as the protagonist's ally, she also has complicated relationships with other characters.
The story about Aizawa Ryaka's kidnapping did not specify whether she was kidnapped by Hideto Banto. Although some readers believed that Aizawa Ryaka was forced to join the Hideto Bando organization, other plots and descriptions of the characters also showed that she had her own motives and choices. Therefore, this problem needed to be carefully considered and explored in the plot of the novel.