Yu Chen and Hiromi Jounouchi happily spent two days in Kamakura before reluctantly returning to Tokyo.
Although Yu had learned about the existence of the Transcendent and the Supernaturalist Association in Tokyo, he didn't seek them out immediately upon returning but instead went back to the hospital to take care of his work.
As the head of the surgical department, Professor Kube was naturally aware that Chen Yu and Jounouchi Hiromi were on vacation, since he was their direct superior and the one who approved their leave.
Professor Kube could understand Yu's desire to take a vacation, especially since he'd been working tirelessly overnight to finish the experiment and had successfully advanced his research to the clinical application stage after healing a chronic patient. It was only natural that he'd want to celebrate and relax with his girlfriend.