This study aims to analyze the brain activity of high school students during a metaverse-based biological classification activity using functional Near Infrared Spectroscopy (fNIRS). For this study, we developed a biological classification inquiry activity by modifiying a metaverse environment featuring a tidal pool and coastal dune, each populated with seven species of animals and plants. This activity was compared with a video lecture covering the same content. Brain activity analysis showed a significant increase in activation in the left orbitofrontal cortex (OFC), right ventrolateral prefrontal cortex (VLPFC), bilateral dorsolateral prefrontal cortex (DLPFC), and frontal pole cortex (FP) during the metaverse-based biological classification activity compared to the video lecture. When analyzing the sub-stages of the metaverse-based biological classification activity,there was a noticeable decrease in activation in the left VLPFC and right FP during the planning stage. Furthermore, group activities resulted in more channels being activated in the bilateral DLPFC compared to individual activities. These results indicate that metaversebased biological classification activities more effectively stimulate motivation and goal-directed thinking, as well as the cognitive processes necessary for devising classification criteria.