Ayayai want to be treated like that toooo!!!SUCH ECSTA-"C"!!!ニヤニヤ "niyaniya" means grin or smirk, and Aya is using it as an adjective by adding シイ "shii" (with the "C" pose for emphasis!). That is, she thinks the Rinnosuke/Keine/Mokou story makes people smile. And she's right.
