FLAGLIA

Iko is a 3rd grade elementary school student who lives with his four older brothers in an old house in Taiyama. There are no parents in the household. According to his brothers, their mother is off working in Tokyo, so they are raising their much younger brother themselves. However, Iko's older brothers have a secret, they are actually immortal sorcerers with an almost eternal lifespan. This is the story of why they became the older brothers of Iko, how Iko is dragged into their whimsical world of magic, and of their summer vacation together as a family.

Synopsis from Anime News Network