At Arista University, Tokyo.
Ever since Yuhi left, Narasaki has watched over Sumire and made sure she is safe. However, not even Narasaki could constantly be with her. He was probably reaching his limit, so he was relieved when Mashima returned. But, it just so happens that Mashima wasn't available today too.
Leaving Sumire alone is too dangerous. Lucifer will undoubtedly try to appear before her if she is by herself. Based on his background research, Lucifer wants to make Sumire his bride. So, he understood why she always needed somebody with her.
Narasaki, and Mashima being busy aside. Normally Nagawa would be around. But not even him?
"I can't believe I'm stuck babysitting," Shin mumbled as he continued to sign some documents.
"Hey!" Sumire exclaimed.
"I know you need protecting, but must it be me? We all know you're stronger than me."
Sumire laughed. "If it comes down to it, I can use you as a human shield!"