Nazotoki-hime wa Meitantei♥
Nazotokihime ha Meitantei
ナゾトキ姫は名探偵♥
The story centers around Hinami, a bookish, eyeglasses-wearing girl, and her two friends. When there is a mystery to solve, she transforms into the clever Nazotoki-hime (literally, Princess Mystery Time).
(Source: ANN)