Akako Koizumi is introduced as the new girl at Ekoda High School in volume one chapter six. First seen speaking with a mirror, it is revealed that she is a witch who wishes nothing more than to enslave the hearts of all men. She is easily angered when she is told that only one man can resist her charms: the Kaitou KID.
When she makes her first appearance at school during Valentine’s Day, she is instantly surrounded by men who beg for a chocolate from her. When Kaito Kuroba appears, she slaps him for dare thinking she would just hand one over when he holds chocolate from others in hands. She tells him that he must forsake those and only accept her. He refuses, leading her to know how Kaitou KID is.
During KID’s heist, she creates a voodoo doll of the thief. Using pain, she leads him to her home within a forest where she tries to bend his heart to her will. KID gets lucky when her trap card magic circle becomes buried in a freak snowstorm, allowing him to escape her spell. KID teaches Akako that magic should be used for others.
In the next chapter, Akako tries to take out the competition for Kaito Kuroba. She goes and separates Aoko Nakamori from being Kaito’s ski partner by using a love sticker on Kaito and making Aoko feel somewhat lackluster. It doesn’t work since Kaito was never affected by the sticker at all.
As the series progresses, Akako becomes a friend or at least a helpful enemy to Kaito. She becomes touchy feely and speaks in a more relaxed tone around him. Akako is still is up for the challenge of winning his heart, but she rather have him alive and happy before she goes after him again. Don’t take it wrong. She has tried to take him out but decided that he was much too important as a friend to kill him.
In her most recent appearance in the manga chapter 23: Black Star/ DC anime ep 219 special and within the first DC OVA, she is shown to be able to see the future and speaks of these visions in prophesies.
Akako is a complex woman. She wants people to see her as a powerful figure. From the very beginning, she has the power to back up her instant popularity. Her charm, her royal presence, her mere existence makes herself as if she was a queen. No one in class seemed to rise up about her sudden popularity though it can be seen that more than one girl was upset by the whole thing.
She closes herself off. Throughout the series, it is never shown if she interacts with her classmates other than Aoko Nakamori and Kaito Kuroba. She seems to keep herself quiet in class if Hakuba did not realize that she was his classmate. Then again, Hakuba would have no real reason to notice her so that point is up in the air. Akako is surprised how friendly Aoko is when she was trying to steal Kaito away for the ski trip. She is completely off balanced by her quick use of ‘Akako-chan’ and when she seems to tease Akako of having a crush on Kaito.
This isolation can also be seen with her home. It seems to be in the middle of nowhere, completely enclosed by woods. Her manor appears to be quite dark and gloomy with only her and her servant residing within the house. It is possible her residence has played a large part in stunting her social skills.
Though she hides it quite well, she has a vulnerable side when dealing with friendships and bonds. Like said earlier, she is quite surprised when Aoko starts to befriend her. She has no idea what to do though it does seem she is trying. Example of this effort is seen during chapter 10 when she gives Aoko a bracelet said to help her grow up. In addition, she does not kill Kaito because of their growing friendship. She has even impersonated Kaitou KID when Hakuba first started to suspect Kaito, crashing into the heist on a broom.
Abilities: Akako has the ability to use magic, leaning towards stereotypical western magic. She is known to have flown on a broom, summon demons such as Lucifer, create love potions, cast voodoo, enchant objects, predict the future, and attract men within her range.