Okamoto is a girl who attended the same middle school as Kyon, Sasaki, Sudou and Kunikida. She was their class leader and a member of the sports society. Her tasks included bringing worksheets about students' future plans.
Okamoto had curly hair and was considered one of the most attractive students. She had a habit of invading people's personal space, Kyon thought she was a "man-hunter" inside.
She wanted to hold a gathering for a summer break in the second year of high school. She went to a girl's school. She still kept in touch with Sasaki.
Okamoto appeared briefly in the manga, with straight rather than curly hair.