Well, it could be a relationship based on power dynamics. Goku is extremely powerful, and Android 21 is no slouch either. They might engage in battles that gradually turn into a form of respect for each other's abilities. And then, this respect could evolve into a deeper connection. For example, Goku could teach Android 21 about the joys of a fair fight, and she could in turn show Goku some of her unique Android - related skills or knowledge.
Maybe in the fanfiction, Goku accidentally uses a new technique that causes him and Android 18 to be mentally linked. Through this link, they start to understand each other on a deeper level. They then find themselves drawn to each other's strength and determination. But they have to hide their growing relationship from their friends and family who might not understand.
Well, their relationship in fanfiction could be really interesting. Goku is a powerful Saiyan with a pure heart and a love for fighting strong opponents. Android 21, on the other hand, has her own complex personality. In fanfiction, they might start as adversaries. Maybe Goku initially sees her as a threat due to her Android nature. But as the story unfolds, he could discover her softer side. They might bond over their shared experiences of dealing with powerful foes and the challenges that come with their respective existences.
It might also be a story about self - discovery. Android 18 could be exploring her more human side with Goku's influence. Goku, on the other hand, could learn more about the androids and how they are not all just mindless killing machines. The 'lemon' aspect might imply some sort of budding relationship that is full of passion and challenges as they come from very different backgrounds.
Common themes often involve the unexpectedness of their relationship. Since Goku is a pure - hearted warrior and Android 18 was initially an enemy. In lemon fanfictions, there might be a focus on the passion that arises from this unusual pairing. Also, themes related to redemption and acceptance can be found, as Android 18 might find acceptance in Goku's world, and Goku might see her in a new light. This all gets intertwined with the more 'lemon' aspects which are often used to heighten the intensity of their relationship.
A possible plot could be that Android 18 gets injured during a fight and Goku takes it upon himself to protect and heal her. This close proximity leads to the development of feelings, which is where the 'lemon' part might come in. Their relationship could be a secret at first as they are from different 'worlds' in a sense, with Goku being a Saiyan hero and Android 18 being an android once created for destruction.
A possible relationship could be a friendly rivalry. They are both powerful in their own ways. Goku is a Saiyan with incredible physical strength and combat abilities, while Android 21 has her own set of unique powers. They might constantly challenge each other to friendly spars, which would help them both improve their skills and also deepen their understanding of each other.
They might start with some hesitant glances and then progress to small touches during their training sessions together. Eventually, they could share some passionate embraces.
One plot could involve time travel. Android 1 travels back in time and meets a younger Goku. At first, Goku is suspicious of her, but as they interact more, they start to care for each other. Android 1 tries to help Goku in his battles against the Saiyans in this timeline. Their love story unfolds as they try to change the future for the better, with their relationship being a key factor in uniting different factions in the fight against greater threats.
Well, one possible plot could be that Goku realizes his true feelings for Android 18 over time. They might start off as friends who train together. As they spend more time, Goku discovers her softer side that was hidden beneath her tough exterior. And then, they gradually fall in love and decide to get married, facing all the challenges from their friends' surprise and the potential threats from villains who might see their union as a threat to their evil plans.
Through shared battles. When they fight side by side against common enemies, they start to trust each other more. For example, in a fight against a group of powerful androids created by a mad scientist, they rely on each other's strengths. Goku uses his martial arts skills and Android 21 uses her technical abilities to analyze the opponents' weaknesses.