According to official website, teen mystery anime series Hyouka will be getting new opening and ending theme songs.

The new opening theme will be titled “Mikansei Stride” which was sung and written by Saori Kodama. Kodama sang the theme songs of Negima!?, IDOLM@STER: XENOGLOSSIA, and many more.

While,  Satomi Satou (Ritsu – K-ON!; Wendy – Fairy Tail) along with Ai Kayano (Inori Yuzuriha – Guilty Crown; Mogana Kikaijima – Medaka Box) will be performing the anime’s ending theme song “Kimi ni Matsuwaru Mystery.”  Satou and Kayano are both cast members of the anime series, playing members of Classic Literature Club  Eru Chitanda and Mayaka Ibara, respectively.

Both CDs will be released this August.

[Source]