I, Star, am excited! This trope is one of my favorites to watch since it can have many spins to the main plot. Sometimes it’s a fluff episode made to be a break from the main story and sometimes a turning point in the plot that adds more drama. So without further ado onward to the rest of the post!
Fruits Basket

Chronically from episode 42 (18 or Season 2), Tohru, Yuki, Kyo, Hanajima and Ueno’s class takes a trip to Kyoto during the changing of the maple leaves. It’s nice seeing them away from family drama and bringing it back to the OG group that started it all. It’s a moment of growth to see how they have changed and grown since the beginning of the series.

Another
In episode 8, the class that is haunted by the ghost thinks the curse is only in the classroom. They quickly realized that this is not the case. The plot progresses even though they don’t return to school. This episode is the rising action to what would be act 3 of the story. The beginning of the end.
FREE!

So in this moment I will mention episode 5 where they decided to train in open water as a summer training camp. The situation that occurs helps strengthen the relationship between two of the main cast.

Cardcaptor Sakura
In episode 17 of the original series, Sakura goes on a trip with her class to the beach. Like most episodes, this one introduces another card that she and Syaoran must capture. The two have their first civil conversation as they work together to get the card before it causes more damage.
Full Metal Panic

In episode 4, the class board’s a plane to take them to Okinawa only to get hijacked and Kaname to be taken hostage. This leaves Sousuke to save her from experimentation trials. This episode really paints a strong picture about the kind of danger that Kaname is in.
This blog says a lot about why we remember them haha.
AishiteLOVEru,
Star