From Mousou Scans:

Ogiwara Umi is an ordinary sixteen-year-old girl with an extraordinary older brother. Ogiwara Haruto is an up-and-coming star actor, and everywhere he goes girls call his name. This would be difficult for any little sister, but Umi has it particularly hard ~ she not only has a brother complex, but she’s actually in love with her brother! But perhaps the more important question is ~ does Haruto feel the same?