my story about seven magical big sister

Set in a fictional version of Japan, the story follows Nishino Manan, a plain and average 10-year-old boy who lives in a house filled with seven older sisters. Each sister has been bestowed with magical girl powers by seven guardians to protect Earth from an evil realm called the Nemesis World. The Nemesis World is led by five generals: Rook, Joker, Jack, Diamond, and Heart.

Manan discovers his sisters' secret powers early on and promises not to interfere, but over time, he becomes a frequent target for the Nemesis monsters. As the story progresses, Manan grows from 10 to 13 years old, and by then, being kidnapped has become a mundane part of his life. The interactions between Manan and his sisters often lead to comedic, action-packed scenarios.