Kamen Rider Zi-O & Kamen Rider Decade X

After defeating their enemies and bring peace to the world, Sora and her friends lived their life.

Years past, Sora didn't hear any news from her friends anymore which she felt something is wrong until her younger sister Natsumi show her the pictures that Tsukasa had taken during their journey.

Sora notice the pictures lost all color leaving blank like her friends are not there anymore even Tsukasa. Sora worries about her nightmare about a new enemy who will start a World War against humanity.

Will Sora able to find the answers she need? And saved her friends?

Or it will be too late?