ONMYŌ☆SQUARE is an original drama CD packaged together with the 2nd Sennen Makyō DVD.
In Kyōto, at the Keikain Main House, Yura returns home to find that her room has become a radio studio! Yura is shocked when she hears "it's for transmitting internet radio!" from the excited trio of Akifusa, Masatsugu and Pato. Ryūji and Mamiru show up and, ignoring a disgruntled Yura, begin the radio show "ONMYŌ☆SQUARE".
What is the purpose behind this radio show? Who's listening to it in the first place!? Just like their magnificent Onmyōjutsu, the Keikain House's radio show becomes a hit...! And what is the fate of Yura, who has been dragged into it!?