You could have a story about a time traveler who has to fix a mistake in the past to save the future. Simple but exciting!
Well, a manga based on a post-apocalyptic world with survivors fighting for resources and building a new society could be interesting. It offers a lot of room for character development and exciting plotlines.
You could go for a dynamic action scene to catch the eye. Maybe a hero in mid-leap or a big explosion.
Try making custom-built shelves with dividers for each manga series. That way, you can easily find what you're looking for and it adds a unique touch to your collection. Also, consider adding some LED lights to make it stand out.
You could go for a bold, single-color background with a detailed character in the foreground. It makes the character stand out.
You could use stackable plastic bins to keep your manga organized and easily accessible.
One idea could be a story about two rivals who gradually develop romantic feelings for each other while competing in a sports tournament.
One-shot manga ideas could include a romance that blossoms in a single encounter at a coffee shop. Or a story of a young artist creating a masterpiece in one intense night of inspiration. Maybe a tale of a superhero saving the city from a unique threat in a matter of hours.
A magical girl who inherits her powers from a long-lost ancestor and must battle dark forces to unlock the secrets of her family's past. This could have elements of mystery and adventure.
One idea could be a forbidden love between a human and a supernatural being. Like a vampire and a normal girl.
You could go for a classic Sailor Moon look with a short skirt and sailor collar. Or try a gothic Lolita style with lots of lace and dark colors.