Two reasons

A glint of surprise flashed across the Shogun's eyes as soon as he recognised that familiar voice.

Seeing his sister walk into his private meeting area without prior notice, a frown appeared on his face as his gaze followed her.

Surprised at the Empress's presence to the meeting, plus the opposing aura she carried with her, the Daimyos bowed their heads slightly to acknowledge her presence.

After all, she was their Empress, and a sister to their Master, the Shogun.

They ought to show her that respect no matter the turmoil going on in their heads as a result of her opposition.

"Himiko, what brings you here?" The Shogun asked as he continued to stare intently at her.

The Empress was silent until she had taken her seat at the other head of the table.

"I was worried about our inability to find one girl after so many years, so, I had to come."