It will start October 5th, 25:20 - 25:35 (or 1:20 - 1:35). (This is right after 49, Satou Shouri's drama, which will be the next drama to air in the time slot Kamen Teacher is currently airing in.)
Kitayama plays the lawyer. Other characters will only include the judge, the prosecutor, the defendant/accused, and the witness. As it's a comedy, all the characters have their own quirks. Even the cases are weird and quirky. For example, on the official website, it says a woman died by suffocation, and her husband surrendered himself, but what's weird is lots of choux creme were stuffed in her mouth!
Source: Official Website | Oricon Style