According to MyCom Journal, two cross over anime episodes of SKET Dance
were announced to be aired in September. They are based on a special collaboration manga of the two published in Weekly Shonen Jump on April 11th. The characters of Sket Dance will appear in the Gintama anime on September 26th and Gintama characters will appear in the Sket Dance anime on September 29th.
Source: MyCom Journal