Rider Time: Kamen Rider Zi-O vs Decade

Both focus on high school students trapped in their school and forced to fight.

However, Girl Gun Lady has the characters going into an alternate reality in-show, while Kamen Rider Zi-O VS Decade is just full-blown set in a reality that is not the one from the main TV show.

Entertaining big families that come close to heart.
The way both dramas deal with family-only dynamics is peaceful.
Full of comedy.
Heart-filling romances.
Double in-law couples.

Both feature Kamen Riders from multiple series
Both have a murder mystery to be solved
Both are spinoffs from a main series