We report two cases effectively treated with Kampo medicines for comorbid sleep disorder in developmental disorder. Case 1 was a 15-year-old woman diagnosed Asperger's syndrome, and her main complaints were difficulty in rising, difficulty in falling asleep and fatigability. We thought that the symptoms might be caused by in and ketsu deficiency, which lost control of kanki hyperactivity and evoked tension/excitement state easily. The difficulty in rising was improved with yokukansan and kambakutaisoto and she was able to go to school every day. Case 2 was a 17-year-old man diagnosed the attention-deficit/hyperactivity disorder. His symptoms were difficulty in rising, feeling of weariness, fatigability, and frequent tension/excitement state. The previous use of shokenchuto had improved the symptoms slightly. After shigyakusan was added to cure kanki dysregulation, he succeeded in going to school every day. In the oriental medicine, ketsu has important roles in mental stability and sleep, whereas qi and ketsu tend to be insufficient in childhood. Our results suggest that replacement of in and ketsu would be useful in treating comorbidities in developmental disorder.