It’s now confirmed that OOO – Den-O – All Rider: Let’s Go Kamen Rider will have a set of net movies, just like how Kamen Rider Decade: All Riders VS Dai-Shocker and Kamen Rider W Forever: A to Z/Gaia Memory of Fate had net movies. This seems to be a new tradition that Toei have started.
The title of this is “Net Version OOO – Den-O – All Rider: Let’s Go Kamen Rider: Let’s Go Net Movies ～Do Your Best and Investigate! Your Riders only 48～”
According to the magazine, Tokusatsu Newtype, there will be 48 episodes where they will go through constellations and blood types of various Riders.
Kamen Rider OOO has an request on behalf of all the Kamen Riders.
In the net movies, Hina’s father will be General Shadow.

The current confirmed cast is
Shu Watanabe – Eiji Hino
Ryosuke Miura – Ankh
Riho Takada – Hina
Fumiki Yoshikawa – Naoki (A new character in the movie)

Voice Only:

Toshihiko Seki – Momotaros
Koji Yusa – Urataros
Shinichiro Miki – Sieg
Tomokazu Sugita – Kivat III
Hidekatsu Shibata – General Shadow
Mark Ookita – Decade Driver
Keisuke Kato – Kamen Rider Ixa
Hidenori Tokuyama – Kamen Rider Kick Hopper

In case you’d like to discuss these matters, please do visit our forum.

Source: Tokusatsu Newtype, April Issue and the offical site of the net movie