An extended one for Mugihito, the voice of the Alien Captain, who played Jean-Luc Picard in the Japanese dub of Star Trek: The Next Generation — including a part where the aliens randomly turn into TNG lookalikes. At one point he watches the movie Excalibur, specifically the part where Patrick Stewart's character vainly attempts to lift the sword from the stone.
He also briefly turns into Keel Lorenz, also voiced by Mugihito.
There are some chalkboard gags that exhibits this. One episode there's a scribble saying "Embarrassing StaXment Are Prohibited" this refers to Aika Granzchesta'sCatch Phrase. Aika and Becky are both voiced by Chiwa Saito.
Kinda, for Akane Serizawa. She's voiced by Miyuki Sawashiro, the VA of Mint Blancmanche. Both characters are obsessed with mascot costumes.
In the OVA, Ichijou has the same hairstyle and school uniform as Kafuka Fuura. Both are voiced by Ai Nonaka.
Averted by Fumiko Orikasa, VA of Himeko, with Kirara from Samurai 7 and Yuko Okonogi from Dennou Coil. Who could have thought that Himeko would have the same VA for a mature older sister and a mild mannered girl?
Also, Rukia now has an ahoge and blue hair, as well as being the resident idiot.