The plan for the 105th is up.
https://news.yahoo.co.jp/articles/42a3ae99515a950edf220297f82124e33ce12711
Title: Come Come Everybody
Heroine: not decided but there will be 3 different heroines (see 'plot')
Screenplay: Fujimoto Yuki (Hanadan 2005, asadora Chiritotechin, taiga Taira no Kiyomori)
Plot and other facts: This asadora will have 3 different heroine characters, namely the grandmother, mother, and the heroine herself. The main theme is a family that spans over generations but tied by English language. The grandmother spent her youth in pre-World War 2 era as English broadcaster in a radio station, but lost her husband during the war and left her children to go to the US. Her daughter (the 2nd generation heroine) initially disenfranchises the grandmother and English language, but it's Western music that saves her. The third generation heroine loves history and English language.
The last heroine is probably a youngster (sub-2000 liner) and will be drawn from audition. Honestly, I don't trust NHK's asadora heroine audition post-Hanbun Aoi. The result speaks for itself, they still cast superstars in the end anyway. I guess there are vanishingly small chances this role could ever go to any other than Makita Aju and Ashida Mana.
The bar is clear though, the actresses must be competent in English, although it's perfectly possible that they just yank any top-tier actresses and hone their English ability in intensive class lol. NHK will do anything to ensure no newcomers climb that ladder.
Broadcast is set at Fall 2021