From SaltyPotatoesTrans:

Noboru, who has an older brother that was an ex-actor, had a strong admiration for Kuriwaki Tsubasa, a Top Idol Actor. Every day he remembers his efforts for his acting career when he saw him long ago at the studio. But one day, when he returned to get the item he forgot in the classroom, he suddenly comes across Kuriwaki-kun dressed up as a girl?! Attempting to run, still in confusion, Noboru was hit by a blunt object and had his picture taken after receiving fellatioㅡ

“This is a secret between us.” Kuriwaki attends school dressed up as a girl due to circumstances. Kuriwaki is blackmailing under the name of “observation." Noboru’s life of being Kuriwaki-kun’s underling starts!