Kamen Rider Build: Raising the Hazard Level ~7 Best Matches~ (Season 1)

As Kiryu Sento prepares for the proxy battle against Kamen Rider Grease, Nariaki Utsumi appears and offer his help.

First Chapter 0.0
Air date: 2018-02-05
Runtime: 20 min
Overview: Nariaki Utsumi appears to help Build prepare for the proxy battle with Grease. This chapter takes place immediately after Sento obtains the Fullbottles from Hokuto and Seito in Episode 21, but one week prior to the scene where Build charges at Grease at the proxy duel.
Next Chapter 0.0
Air date: 2018-03-12
Runtime: 20 min
Overview: This chapter takes place immediately after Sento obtains the Fullbottles from Hokuto and Seito in Episode 21, but one week prior to the scene where Build charges at Grease at the proxy duel. This episode features the debut of Build's ToraUFO, KirinCyclone and KujiraJet Best Match forms and Hell Bro’s.
Final Chapter 0.0
Air date: 2018-04-30
Runtime: 20 min
Overview: This is third and final installment of Kamen Rider Build: Raising the Hazard Level ~7 Best Matches~. It was released on alongside the DX Same and Bike Fullbottles in one set. It features the only appearance of Build's Same/Bike Form. This chapter takes place one month after the previous episode.