One interesting plot idea could be that Trunks and Goku have to team up to face a new, extremely powerful enemy from another dimension. This enemy has powers that neither of them has seen before, forcing them to quickly learn to combine their unique fighting styles. For example, Goku's Instant Transmission and Trunks' sword - fighting skills could be used in creative ways to counter the enemy's attacks.
A plot where Goku and Trunks accidentally switch bodies due to a magical mishap. At first, they struggle to adapt to each other's powers and ways of life. Goku in Trunks' body has to deal with the responsibilities on Earth while Trunks in Goku's body has to figure out how to interact with Chi - Chi and the others at home. This situation leads to many comical and also some intense moments as they try to find a way to switch back while also dealing with any threats that come their way.
One idea could be that Michiko is a new character who has a special power that Trunks needs to defeat an emerging threat. For example, she might be able to control time in a different way than the Time Rings. Another plot could involve Michiko being from a lost part of the Saiyan history and Trunks discovers that she holds the key to unlocking new Super Saiyan forms. Maybe she has a connection to an ancient Saiyan prophecy that Trunks has to help her fulfill in order to save the universe from a great evil.
One interesting plot could be that Pan and Trunks go on a journey to find a lost Dragon Ball. Along the way, they encounter new enemies and have to use their combined skills to defeat them. They might also discover a new form of energy that is related to the Dragon Balls.
One idea could be a time - travel fanfic where Bulma accidentally sends Goku back in time to a period before they met. Goku has to figure out how to get back while also dealing with the differences in that time period. Another could be a story where Bulma creates a new device that gives Goku a new power - up, and they have to test it out against a new, powerful enemy. A third idea is a fanfic set in an alternate universe where Goku and Bulma are the rulers of Earth and have to deal with diplomatic issues with other planets.
One idea could be Trunks and Mai going on a time - traveling adventure together to prevent a new threat in an alternate timeline. They could use their combined skills and knowledge to outwit the enemy.
One idea could be a story where Vegeta and Trunks train together in a new, super - intense way. They could discover a new form that combines their Saiyan powers in a unique way. For example, they might find a way to fuse their ki into a powerful energy blast that can defeat even the toughest enemies.
In a fanfiction, there could be a scenario where an ancient prophecy foretells of a combined power of Trunks and Goku being the only thing that can stop an impending doom. They start training together to master a special fusion technique that no one has ever attempted before. Along the way, they face challenges not only in their training but also in dealing with their own egos and differences in fighting styles.
One idea could be Goku Jr facing a new, powerful enemy that has a unique power related to time manipulation. This would force him to train in ways he never has before and seek help from unexpected allies, like some of the older, wiser characters from the original Dragon Ball Z series.
One idea could be Goku and Gohan going on a special training journey to a new planet with unique gravity and energy sources. This would force them to adapt and develop new techniques together.
A possible plot in the 'dragon ball goku and bulma lemon fanfiction' could be that Bulma is working on a project that requires a special ingredient or power source that only Goku can help her find. As they search together, they encounter various challenges like dangerous terrains and powerful creatures. Along the way, their friendship deepens and they learn more about each other's strengths and weaknesses. This could lead to them developing new powers or techniques that they bring back to their friends in their normal world.
A plot could involve Bulma creating a new device that Goku needs to use in order to defeat an extremely powerful enemy. Goku has to learn how to operate this device with Bulma's guidance, and they face many obstacles along the way. This would show their cooperation and how their different skillsets complement each other. It could also lead to some comical moments as Goku tries to understand the complex technology. Another interesting plot could be that they are both transported to an alternate dimension where the rules of the Dragon Ball world are slightly different. They have to figure out how to adapt and find a way back home while also uncovering the secrets of this new dimension.