She is Hatsuhi's coworker (at Takebo toy company) who likes Hatsuhi and go to such lengths to make him her man.
Souko Aiko is created by Chihiro Harumi, and she has no information regarding any inspiration used to create her. Aiko first appears in Koi wo Suru no ga Shigoto Desu chapter 2 in volume 1.
She is a beautiful woman with blonde hair, and Aiko enjoys wearing clothes that reveal her cleavage in order to get Ryou to notice her.
Aiko is quite determined and not ashamed to use her body to get Ryou's attention.