The current study elucidated the epidemiological characteristics of sapovirus (SaV) and human astrovirus (HAstV) associated with gastroenteritis among children in regional populations of Nara Prefecture, Japan, during the 2009/2010–2014/2015 seasons. The SaV detection rate was 7.5% (71/948) according to reverse transcription-polymerase chain reaction. A high SaV detection rate of 13.5% was observed among children 4 years of age. The highest SaV detection rate was observed in June (19.2%), followed by July (11.1%). The detected SaV included 7 genotypes: GI.1, GI.2, GII.3, GII.1, GI.3, GII.2, and GV, in order of decreasing prevalence. In comparison, the HAstV detection rate was 4.2% (40/948). The HAstV detection rate among children 4 years of age was 12.2%. The HAstV detection rate was highest in July (13.9%), followed by May (10.5%) and August (6.7%). The detected HAstVs included genotypes 1, 4, 6, and 8. The most prevalent genotype was 1, followed by 4 and 8. This report provides an epidemiological overview of SaV and HAstV infection in Nara Prefecture, Japan.