The rising of the shield hero's sister

Iwatani Ana is the younger sister of Iwatani Naofumi , it has been a couple of days since he didn't come home, no one have heard anything from him and that worries her, she try's again to go to all the places her older brother would go, when she comes to the last place she is transported to another world by a book, a good thing and a bad thing came out off that, she found her brother but they have to fight monsters and a corrupted country to get back home.

What Ana doesn't know is that she may have more to do with this new world then she thinks.