Identity can be a theme. A character may question their identity as a Gundam pilot or a citizen of a certain faction when they fall in love with someone from the other side. And of course, the overarching theme of love itself. How it can transcend boundaries, whether they are political, ideological or related to the technology of the Gundam world.
One possible theme could be the combination of different power systems. Naruto has its chakra - based powers and Gundam has advanced technology. How these two interact in a fanfiction could be an interesting theme. Another theme might be the cultural clash. The ninja world of Naruto and the more futuristic, often military - focused Gundam universe could lead to some interesting cultural exchanges in the story.
One of the best Gundam love stories could be the relationship between Amuro Ray and Sayla Mass in the original Gundam series. Their connection was complex, with shared origins and a mutual understanding in the midst of the chaos of war. They had a bond that was both about camaraderie and a deeper, unspoken affection that developed as they fought side by side.
A third theme might be the pursuit of dreams. If one or both of the lovers had big dreams, like traveling the world or becoming an artist, their love would be intertwined with their individual pursuits. They might have to choose between love and their dreams or find a way to make both work in the context of their relationship.
One possible theme could be sacrifice. In 1941, during the war, lovers might have to sacrifice their time together, or one might sacrifice their safety for the other. Another theme could be hope. Despite the dark times of war, their love could be a source of hope for a better future.
One possible theme could be nostalgia. Since it's related to 1989, it might evoke a sense of longing for the past, especially for the time when the love story took place.
In a 2023 love story, the theme of second chances might be present. Maybe someone had a bad breakup in the past and in 2023, they meet someone new who gives them a chance to love again. Technology can also be a theme. People might have met through a dating app in 2023 and their relationship developed from there. And of course, the theme of family could be there. A couple in 2023 might be building a relationship with an eye towards starting a family in the future, so they are learning to support and care for each other like a family unit.
One possible theme could be social change. In 1950, society was evolving, and a love story might have been influenced by new social norms. Another theme could be sacrifice. The lovers may have had to sacrifice personal desires for each other or for their families.
Another theme could be hope. People in 1948 were looking forward to a better future after the destruction of the war. So the love between two people could represent the hope for a new start, both in their personal lives and in the broader context of the world around them. It could also be about the theme of change. 1948 was a year of significant change, and the love story could revolve around how the characters adapt to the new social, political and economic changes while falling in love.
One possible theme could be sacrifice. Given the historical context of 1917 which might involve war or social upheaval, the lovers may have to sacrifice their own desires for the greater good or for each other.
Another theme might be perseverance. The couple in the '1982 love story' could have faced various difficulties, such as differences in social status or family opposition. But they persevered in their love. And also, discovery could be a theme. As they got to know each other in 1982, they were constantly discovering new things about one another, which deepened their connection.