Kagami and Tsukasa's seiyuus (Katou Emiri and Fukuhara Kaori) were on the
A&G Anisupa radio show on Saturday and Washizaki Takeshi and Asano Masumi, the hosts, gave them a cake for their characters' birthday.
I've made a
blog post about it, with photos. There are more pics on the show's site, which is linked to from the blog post.