|Anime debut||Episode 3|
|English Voice||Paul Locklear|
He is a slender man with short brown hair and brown eyes. Sasaki is often seen wearing a green sweater with a white collared shirt underneath and slacks.
Sasaki is first seen during the orientation introducing Ryoko Tamiya as the new assistant teacher, due to Mr. Matsuyama's injuries. Later he tries to asks Ryoko out on a date, but is politely turned down due to a previous engagement.
During Mr A's attack on the school he quickly grabbed the man and tried to get him to leave, but is knocked unconscious. He soon gets his injuries treated and collects Ryoko's class and calmly leads them to safety. He along the rest of the school react to the explosion from inside the school.
He and the rest of the school faculty attend a meeting where they discuss Ryoko's pregnancy and the situation pertaining the father. When Ryoko leaves, quitting her job, Sasaki is the only that tries to stop her.