A short Ben-Tou CD drama comes with the first issue of the Shueisha light novel magazine Super Dash & Go. I'm not sure if this is all of it, but here is a clip of the drama from NicNico Douga. As usual, the clip from Nico takes a long time to load.
It stars Wakamoto Norio, Shimono Hiro, Ise Mariya, and as the novel's author, Asaura, writes in his blog: "...for the first time ever, Yuuki Aoi's wonderful voice mimicking Wakamoto-san."
I actually don't think she comes all that close to Wakamoto's voice, but it's an amazing attempt anyway.
In the brief drama, Wakamoto plays Shimono's father, and they get very close in the bath....