Other name: エスイー, エス・イー, System Engineer, ΣΕ, مهندس نظام
Summary: Oka Shirou (22) is on his last day as a Computer Science university student and he finally works up the courage to chase after a girl he often sees on the train reading a programming book. As he reaches out, he grabs her bag and accidentally spills the contents. Music player, books, and a...SEX SLEEVE?! The girl snatches it and darts off with tears in her eyes. Oka resolves to leave the failed encounter in the past and focus on his new job as a System Engineer. Little did he know, he would meet the girl once again...