Kazutaka Ohtsuka Sensei mentioned about some videos on youtube and said to look up "jujutsu duo". Not sure why yet, whether it was for entertainment value or to see a different form of 'competition'.

Here are some clips

Adult Jujutsu Duo

Children's Jujutsu Duo

However, I quite like watching these things: Daiwado Jujutsu , Takenouchi Ryu Jujutsu , Taisha Ryu Kenjutsu instead.