Part-time sitter for 5th-grade boy and 1st-grade twins (a boy and a girl)

We are a Japanese family with a fifth-grade boy and first-grade twins (a boy and a girl). While my husband or I are usually at home and spend time with the kids, there are occasions when both of us need to be away. Our children are accustomed to spending time with a nanny. They are very friendly and energetic, but they also understand how to behave appropriately. We are looking for a nanny to pick up our children from the school bus stop, which is conveniently located just around the corner from our home, and spend time with them at home until we return. Responsibilities include assisting the children with their homework, supervising dinner time, and ensuring they take showers before bedtime.