Sasaki started out at Weekly Shonen Jump some time before the start of the series. He was the editor that worked with Nobuhiro Mashiro as his editor before the gag manga he created got canceled. Sasaki pressured him to work again on a new series but Nobuhiro continued doing his own work as an assistant until his death. By the time Mashiro and Takagi begin to try and get publicized at Jump, Sasaki has become the Editor in Chief of the Weekly Shonen Jump with the other Editorial Departments seeing to him. Mashiro recognizes him as his uncle's old editor from the funeral that was held after his death. He understands what it takes to make a great manga series like Crow and that is a love for manga like Nizuma has and tries to guide the two young mangakas to understand how much they have to put in in order to become successful in the manga industry.
Creation
The character of Sasaki was created in joint collaboration by mangakas Takeshi Obata and Tsugumi Ohba. It is more than likely so that Sasaki represents some of the Executive Editors both Obata and Ohba have met and worked with in their lives as mangakas.