Seikatsu Shuukan The Animation(2019)

Wanna be my little brother?

Seikatsu Shuukan The Animation is a comedy series following Shuntarou, a young man tormented by his three cruel younger sisters—Ayaka, Chiaki, and Fuyuno. Desperate for kindness, he dreams of having a gentle older sister instead. When a mysterious game suddenly appears in his life, it sets off an unexpected transformation that makes him younger. As Shuntarou regresses in age, the dynamic with his sisters shifts in unpredictable ways, leading to absurd situations and comedic chaos. The series blends supernatural elements with family humor as Shuntarou navigates his bizarre new circumstances and searches for the affection he's always craved.