Masumi Takeda is brought back into the operation to help the group gain access to the equipment they need. The search for answers becomes a full technical operation, with the adults concentrating on decoding the drive while Akira watches their movements and looks for an opportunity to obtain the Testament himself. Akira’s involvement makes every decision more dangerous because he understands the people he is watching. This is not simply a contest between hackers trying to outsmart one another. Everyone involved knows enough about everyone else to predict what they fear, whom they will protect, and what mistakes they are likely to make.

The clues eventually lead the investigation back to Kagamiyama Private High School, turning what began as a computer problem into a physical search through familiar locations. Teru refuses to wait safely outside the investigation. She studies the clues, thinks about Akira’s behavior, and realizes that being watched does not necessarily make her powerless. If Akira is observing what the group does, then Teru can make decisions based on what she wants him to see.

That development is the most interesting thing about Volume 13 because Dengeki Daisy has spent much of its story surrounded by people with extraordinary technical abilities, yet Teru increasingly succeeds by understanding something none of them can program: other people.

The difference matters because Kurosaki’s intelligence often makes him less flexible. He sees danger and immediately begins eliminating possibilities. Protect Teru. Control the information. Reduce the risk. Teru moves in the opposite direction. She watches people, tolerates uncertainty, and considers possibilities that make everyone else uncomfortable. That approach can be reckless, but in Volume 13 it also makes her essential to the investigation.

By the time Teru makes her decisive move near the end of the volume, she is no longer simply the person everyone is trying to protect while the experts solve the mystery. She has become one of the people changing its direction. The hackers may control the computers, but Teru is beginning to understand the system they keep overlooking: the human beings using them.