Raise Your Hazard Level: 7 Best Matches
Toei Tokusatsu Official Youtube Channel special. Comes chronologically after episode 21 and before episode 22 of Kamen Rider Build.
Part 1 aired February 5, 2018.
Part 2 airs March 15, 2018.
Part 3 is a DVD exclusive to be released in April 2018 with the Same/Bike Full Bottle Set from Kamen Rider Toy Web.