As an intern at a cognitive science institute, Jeong-yeon meets Yu-geon, his former high school tutor.

Participating in a VR test for an emotional reaction experiment, Jeong-yeon faces his own feelings through questions.

For the first time late, Jeong-yeon appears in the laboratory injured as in childhood, and Yugeon reacts angrily when he sees him.

As the final experiment finally begins, Yu-geon and Jeong-yeon's hidden feelings begin to reveal themselves.