I've finally found out some information on the special drama cd of Shana II below after receiving and listening to it.
It seems that this was a special extra item for the April 2008 issue of
Animage.
The story is a lighthearted one where Shana and Wilhelmina are shopping at a shopping mall and Shana finds a lost little boy looking for his mother. There's some funny parts in it where Shana is helping the little boy find his mom while also playing and keeping him company. She doesn't know that Wilhelmina, Yuji, Yoshida and the others are following her around.