A frequent lamentation of many writers is, “I have all these characters, but no plot!” or “I’ve come up with this awesome world, but have no story!” Though this may cause trouble if you really wanted to tell a gripping and exciting tale from the get-go, I don’t think it’s necessarily a problem in and of itself. This is because not all stories need a plot, or at least what many people might consider a plot. These stories focus on the small moments of life and relationships, and fall under the genre umbrella of slice-of-life.
Now, you might be thinking, “But what if I don’t want to write slice-of-life? What if I want to write sci-fi, or supernatural, or horror?” To which I respond, “None of those are mutually exclusive with slice-of-life.” I’ve written at length about all the misconceptions about genre and the ways in which they can be combined, and slice-of-life is no different. It doesn’t matter what trappings your story has, so long as what your characters are doing is low-key and everyday, even if “everyday” in your world involves spaceships or magic or whatever.
But surely not every genre can combine with slice-of-life, right? Sure. Epic fantasy and slice-of-life don’t really jam. I even think it might be hard to combine horror and slice-of-life, though some of the “I work in X unnamed locale and weird stuff happens here” can fit the bill. Most genres, with enough imagination, can actually work with slice-of-life.
For example, The No. 1 Ladies Detective Agency books are ostensibly mysteries, but are in fact slice-of-life stories about a lady who happens to run a detective agency. The focus of each book is on the characters, their relationships, and their foibles. There might occasionally be a crisis, or a near crisis, but these are easily solved, as are the mysteries, which are secondary to the main “plot”, which is the everyday lives of the characters.
Well, what about war? Even setting aside M*A*S*H and Hogan’s Heroes (sitcoms are slice-of-life, for sure), there are stories like In This Corner of the World, which takes place outside Hiroshima during World War II. The main characters have to deal with bombings and war leaflets and, of course, it ends with the atomic bombing, but the main focus of the story is how the characters continue to try to lead normal lives despite all of that. It’s a war story, but it’s told through small moments of an ordinary family.
The genre which seems to give the most people a hard time, in term of slice-of-life-ification, is fantasy. For some reason, everyone seems set on the idea that if the setting has magic, the characters must go on quests, have epic battles, and save the world. Why, though? We know that there are people in every fantasy setting who go about their non-epic business. Why not write about the guy who runs the tavern where so many adventuring parties start? Why not explore the lengths the item shop lady has to go to in order to get her items? Who's running the temples in your world? How do farmers deal with all the attacks from dragons, trolls, and hordes of the Dark Lord's army? Even if you’ve already come up with characters who have more significant-seeming backstories, that doesn’t mean they have to do stereotypical-fantasy-hero things.
One of my all time favorite slice-of-life fantasy stories is Natsume’s Book of Friends. The main character is an orphaned teenage boy who can see spirits, just as his grandmother could before him. This ability is rare and not really acknowledged by the population at large (the story is set in modern Japan), so he and his grandmother before him are/were somewhat ostracized. He also comes into possession of his grandmother’s old “Book of Friends”, where she wrote down the true names of a bunch of spirits, some of which legitimately liked the grandma and some of which want revenge for having lost their names. Thus Natsume, the main character, has to deal with different spiritual problems, as well the machinations of exorcists who either work with sprits or use them for their own devices. This story is not epic. It’s epically heartwarming, but that’s about it. 99% of the plot is Natsume meeting some spirit who has some problem—usually interpersonal—and helping them deal with it. The conflicts are low key and small, even if they do involve the occasional forest god.
The author, Yuki Midorikawa, could have come up with this character, Natsume—a boy who can see spirits and whose grandma wrote their true names—and lamented that there wasn’t really any plot, but she realized that she already had the plot, because she had the character. It's the same with No. 1 Ladies; Alexander MacCall Smith had a character, Precious Ramatsue, and she was a detective. Plot problem solved.
So if you find yourself with a handful of characters with no plot, why not try slice-of-life for a while? Explore your world and characters in the everyday moments. Even if you do end up with a bigger stakes plot, writing those small moments is a good way to explore character or to write character development scenes that fit into the larger plot. Or you might like the small scale of slice-of-life. Either way, you’ll end up with a story, and that’s the whole point of writing. Slice-of-life is a win-win.