Boys weren't allowed into the legendary school of allegedly all idols.
To see if it even existed, Kou Tennomiya went to that place and saw a string of beauties entering the fortress-like outer gate.
Including his own stepsister.

"The rumor was true......"

When Kou attempted to chat with some girls passing by they looked at him like a piece of garbage, and guardmen jerked him aside and laid him out.
The girls went on merrily as if nothing happened.

"Hrumph."
Strewn like a dirty cloth, a sparkle flitted in Kou's eye.

He went home and consulted his father.

The next day Kou went to the same place, only the guards
from yesterday were now lined up and bowing with respect.
"We've been waiting for you!"

What heaven lie beyond the gate?
What would he have the idols do? Kou speculated excitedly.

All he wants, whenever he wants. It's the start of happy days...

[From DLsite English]