Iwase Aiko was a classmate of Mashiro and Takagi during Jr. High. When she appeared with Miyoshi Kaya at Takagi's house after his suspension, she revealed that she liked him, but didn't want him to be a mangaka. She reappears in chapter 60 as a student at Tooh University along with Aoki Ko. She writes stories for manga.
Iwase has short black hair with a small flip at the bottom. When she reappears later in the story, she has her hair cut slightly shorter, though it still has the same shape. She is considered to be very beautiful by many people, including herself and Miura.
Iwase is very haughty, repulsive and is the type to not hold back her opinions. She is also very inteligent for being the best in her class and ranking second only to Takagi during Jr. High.
Career as a MangakaAiko wrote her first novel while in University, but since she sees Takagi as a rival, she decides to write stories for Shonen Jump artists to see if she can beat him at his own game. Her editor is Hattori, who worked with Takagi and Mashiro. She becomes the writer for Eiji's new manga +Natural. She also teams up with Eiji for a collaboraiton in Crow for a few chapters. After Hattori returns as Takagi and Mashiro's editor, her new editor is Miura. Her writing and plot are praised for being very well made. However, she comes in last place for the Super Leaders' Love Fest.
- Iwase resembles Kiyomi Takada from Death Note another manga by Tsugumi Ohba and Takeshi Obata.
- She placed 10th in the popularity polls.