Another plotline could revolve around their training sessions. Suigetsu wants to improve his sword skills, and Karin, with her sensor abilities, could help him by detecting hidden opponents. In the process, they could develop a mutual respect for each other's abilities and form a deeper bond. They might end up teaching each other new skills and growing as ninja together.
A third plotline could be set in a post - war scenario. Suigetsu and Karin are trying to rebuild their lives. They decide to open a small business together, perhaps a combination of a weapon shop (Suigetsu's interest) and a medical clinic (Karin's expertise). Through the trials and tribulations of running the business, they learn more about each other and their relationship evolves into a strong friendship.
One possible plotline could be them going on a journey together. They might start off bickering like they often do, but as they face challenges on the road, they gradually become closer friends. For example, they could be searching for a rare ingredient for a medical experiment Karin is doing, and along the way, Suigetsu protects Karin from various threats.
One possible plotline could be that Naruto discovers a new type of bathhouse in the Hidden Leaf Village that uses lemon - scented oils for relaxation. He tries it out and has a series of comical interactions with the other villagers who are also there. Maybe he accidentally slips on a lemon - scented soap and his friends have to help him up, all while sharing some light - hearted banter.
One possible plotline could be that the Crystal Gems are captured by a new and powerful enemy. They have to use their wits and the unique abilities of each gem to find a way to escape. For example, Garnet might use her future vision to anticipate the enemy's moves, Pearl could use her combat skills and knowledge, and Amethyst her shape - shifting abilities in unexpected ways.
I'm not sure specifically about 'lemon' fanfics (which often imply adult content), but there are many great fanfics about Suigetsu and Karin that focus on their relationship development in a more general way. You can try searching on fanfic platforms like FanFiction.net or Archive of Our Own and filter for stories tagged with their names.
Another plotline could revolve around them working together to save a comrade. They have to combine their skills, with Ichigo's brute strength and Unohona's healing abilities. Along the way, they start to understand each other's values better. Unohona might see Ichigo's unwavering determination in a new light, and Ichigo could respect Unohona's calm and collected nature even more. It's a story of friendship and cooperation.
One possible plotline could be a female Goku going on a special training journey. She might discover new powers or techniques and form new friendships along the way. For example, she could meet a character from another part of the Dragon Ball universe and they could team up to face a common threat.
One possible plotline could be them teaming up for a mission. They might have to face a powerful enemy together and use their unique skills, like Naruto's Rasengan and Yugito's ability to control the two - tailed cat, to defeat it. Another could be Yugito teaching Naruto some of the secrets of the Hidden Cloud Village.
A plotline could involve a female character from the Naruto universe, like Sakura, who gets transported to a world where cowgirls exist. There, she meets a kind - hearted cowgirl who helps her adapt. As Sakura shows her medical ninja skills to help the cowgirl's community, the cowgirl is impressed. They become friends and gradually, a romantic connection forms between them. It could be a story of two different worlds colliding in a sweet and non - adult way.
One possible theme could be their deep friendship. They could be shown supporting each other through tough times, like when facing a powerful enemy. Another theme might be their growth as ninjas. For example, they could train together and learn new techniques from each other.
One possible plotline could be a story of Naruto and fem Madara becoming friends against all odds. Given their different backgrounds and beliefs in the Naruto universe, they could start off as enemies but gradually come to understand each other. For example, they might be forced to work together on a mission to save the Hidden Leaf Village from a powerful external threat. Through this, they learn about each other's strengths and weaknesses and develop a mutual respect.
One possible plotline could be that the OC is a new student at the DWMA (Death Weapon Meister Academy). Death the Kid, being intrigued by their different fighting style or personality, decides to team up with them for a mission. Along the way, they face various challenges and enemies, and their relationship grows as they learn to trust and rely on each other.