The natural environment significantly affects the release of human stress and sleep quality. Variations in lighting and color brought about by the sun play a crucial role in the regulation of our physiological functions and circadian rhythm. This study aims to examine the effects of virtual beach environments at different times of the day (including day and nighttime) on relaxation and the promotion of sleepiness, compared to a control group using self-relaxation methods. The research variables included self-relaxation, daytime, and nighttime scenarios, with the nighttime scene featuring a starry sky and a campfire. We analyze participants’ physiological and psychological responses to uncover the impact of virtual scenes and self-regulation on transitioning from stress to relaxation. Psychological questionnaires gauged the levels of relaxation, calmness, and sleepiness. Physiologically, brain waves, heart rate variability, and heartbeat changes were evaluated. The results of our study indicate that all three groups could relax from stress, with participants immersed in the starry sky scene exhibiting the most significant reduction in heart rate and an increased sense of sleepiness. The self-relaxation group showed higher theta waves than other relaxation groups, possibly tied to deep contemplation. Through this study, we gained a better understanding of the effects of natural virtual reality environments on stress relief and the promotion of drowsiness. We plan to use the starry sky with a campfire virtual scene in experiments involving individuals who struggle with sleep difficulties in the future.