【case】 14-year-old boy with Neurodevelopmental Disorders had various physical symptoms following the cold, and he was diagnosed as ME/CFS. Nocturnal hypoglycemia and glucose spikes were observed. We applied tonifying method and dietary guidance. We supported playing marimba as his existential resource.【Clinical course】 5 months after onset, his symptoms improved after adjusting the learning environment, and he was able to get out the onset of ME/CFS. Hypoglycemia and glucose spikes were reduced.【Discussion】 For a case of ME/CFS associated with Neurodevelopmental Disorders, the most effective treatment was to adjust the learning environment to reduce social stress, and to gain the understanding from the surroundings. It was thought that dietary guidance to improve hypoglycemia and glucose spikes, which may be involved in impulsivity, could be established on this basis.