Well, it could start with Android 21 being curious about Gohan. She might observe him from afar at first, intrigued by his power and his gentle nature. Gohan, not knowing this, goes about his daily life. Then, there could be an accidental encounter where Android 21 saves Gohan from a minor threat. This makes Gohan interested in her. They start to have conversations, slowly getting to know each other. As they do, they realize they have a lot in common, like their love for knowledge and their desire to protect the world. This realization makes their relationship develop further.
Their relationship can develop through mutual respect. Gohan respects Android 21's strength and intelligence, while Android 21 respects Gohan's kind heart. This respect can turn into friendship first. For example, they train together, learning from each other's fighting styles. Then, as they spend more time together, they start to notice little things about each other that they like, which gradually leads to a romantic relationship.
Their relationship could also develop through mutual respect. Gohan respects Android 18's power and her ability to make her own decisions. Android 18, on the other hand, respects Gohan's intelligence and his role as a protector. This mutual respect could be the foundation for a romantic relationship. For instance, they could start training together. During training, they would learn more about each other's limits and capabilities. This closeness during training could lead to a spark of love as they see each other in a different light, not just as allies but as potential lovers.
Their relationship could start off as a mutual respect for each other's power. Gohan would be in awe of 18's android abilities, and 18 would recognize Gohan's potential as a Saiyan. As they spend more time together, they might start to become friends, sharing their thoughts and experiences.
Their relationship could be developed realistically by having them work towards a common goal. For example, they might be trying to stop a new villain from taking over the world. As they plan and execute their strategies, they see the best and worst in each other. Gohan might see Android 18's determination even in the face of great danger, and Android 18 might see Gohan's selflessness. These experiences can bring them closer and form a relationship based on trust and admiration.
Their relationship can be developed through shared battles. When they fight side by side against a common enemy, they learn to trust each other's combat skills. For example, if they face a group of powerful villains, Gohan can rely on Android 18's precision attacks and she can count on his brute strength. This mutual trust can be the foundation for a deeper relationship.
Often, it starts with mutual respect. Gohan respects Bulma's intelligence and her ability to create amazing things. Bulma respects Gohan's power and his kind heart. As they spend more time together, they start to understand each other better. For example, in a fanfic where they are stuck on an island, they have to rely on each other for survival, and this shared experience brings them closer.
To develop their relationship, start with small interactions. For example, they could exchange fighting techniques. This would allow them to see each other's strengths and respect each other. Then, put them in situations where they have to rely on one another, like being trapped in a dangerous place. As they work together to escape, their bond will grow. Also, have them share their pasts. The Saiyan can talk about his Saiyan heritage and Android 18 can share her experiences as an android. This will create a deeper understanding between them.
The relationship could develop out of a need for companionship. Gohan, having lost many of his friends and family in battles, is in need of someone who can understand his pain. 18, being an android with her own complex past, also longs for someone to be close to. They meet and initially just offer each other a listening ear. As they talk more, they find that they can comfort each other in ways no one else can. This emotional connection then grows into a romantic relationship, and finally, they marry as they realize they don't want to be without each other.
A possible relationship is that of friends. They respect each other's strength and abilities. Android 18 might admire Gohan's determination and Gohan could be impressed by Android 18's combat skills.
In a fanfiction, Future Gohan and Android 18 could have a relationship based on redemption. Android 18 has done some not - so - great things in the past. Gohan, being the good - hearted Saiyan he is, could see the potential for good in her. He might try to guide her towards a more positive path. This could involve Gohan protecting 18 from other threats, and in return, 18 could use her android powers to help Gohan in his battles. Their relationship could be a slow - burn type, gradually evolving from distrust to a strong friendship or even more, depending on how the fanfiction unfolds.
For Gohan, his character could be developed by showing his struggle to balance his family life with his new relationship with Android 18. He might be hesitant at first because of his responsibilities. For Android 18, her character could be developed by exploring her emotions more deeply. Since she was an android originally, she could learn about love and friendship in a new way through her relationship with Gohan.