Kamen Rider Blade: The Project Rouzer Rider And Sekai!

[Kamen Rider x Reverse Isekai Project Sekai Crossover]

Years after Kamen Rider Blade seal the Joker Undead as the world is peaceful. Kouki Sakamoto and Seiji Ogawa are high school student with different personality, Kouki is short temper, and Seiji is Meme guy. One day they return home, Kouki has a dream and seeing Sakuya Tachibana is in his dream. He explain to Seiji and Kouki that their world is merging with world of Project Sekai so he give them the Buckle to fight. Kouki and Seiji take the buckle before they woke up and see their waifu is become real in the real life world which shock them.

However the Undead is back as Kouki and Seiji chosen to become the next BOARD Rider to fight for the world and the melody of this world. HENSHIN!