Mokke, Wagaya no Oinari-sama. Recommendations
Looking for light-hearted anime with supernatural elements? Both Mokke and Wagaya no Oinari-sama have plenty, especially from Japanese folklore. The main characters in both series are a pair of siblings, one an elementary schooler and one a high schooler; in Mokke it's a pair of sisters, while in Oinari-sama a pair of brothers. In both anime the younger sibling is often targeted by supernatural creatures such as youkai. In Mokke the older sister protects the younger, while in Oinari-sama the younger brother is protected by a third protagonist who is a youkai herself.