C312 Unforgettable mind

Cheng Boyan and Shen Siyu discussed their work to the point of forgetting to eat and sleep. They didn't even know when the practice opened the door and came in.

He stood there watching them for a long time. Seeing that they were not paying attention to him, he focused all of his attention on his work. With a smile, he turned around and walked away.

He laughed because he was happy