Akimoto was born and raised in Chiba Prefecture to a Japanese father and a Filipino mother.
On the last day of the Budoukan concert on August 23, 2009, during the team shuffle, Akimoto was officially made captain of Team K. Akimoto has been featured on every single by the group as she is the Captain of Team K making her a regular featured member for most of their A-side tracks until she was suddenly hit with a scandal in 2010. Since then she has only appeared on A-side tracks from a general election or a rock-paper-scissors tournament. On August 24, 2012, Yuko Oshima replaced her as the captain of Team K.
She is sometimes seen performing with the group during their live appearances on TV when the other featured members are on busy schedules. She has since been involved with sub-unit group DiVA under Avex. Akimoto is also one of the most well-known members among the public, as she was a regular on the popular noon TV show Waratte Iitomo, and as well as appearing in many variety TV shows.
On April 7, 2013 Akimoto announced on her official blog that she would not be participating in AKB48's 2013 general election, and would be graduating from AKB48 to focus on her acting. She plans to continue in the DiVA group. Her graduation ceremony was held on August 22 at the Tokyo Dome, and her final stage performance was held on August 28 at the AKB48 Theater, and has been streamed live by Nico Nico Namahousou