He could be getting married to Ochaco Uraraka. They have a great friendship and there are many hints in the series that suggest a deeper connection between them. Their personalities complement each other well, with Deku's determination and Ochaco's cheerfulness.
Another storyline might involve Deku having to face some sort of villain threat right before the wedding. He has to balance protecting his loved ones and ensuring the wedding goes on as planned. Maybe a new villain emerges who wants to disrupt the harmony of the event. But with the help of his friends and his own heroic skills, Deku manages to defeat the villain and still have a wonderful wedding.
In 'deku meets future deku fanfiction', perhaps the future Deku warns the present one about upcoming threats. He could tell him about villains he'll face in the future and how to defeat them. This would give the present Deku an edge in his battles and also in his growth as a hero.
Another plot might involve the older Deku being from an alternate timeline. He shows the younger Deku different ways he could have developed his skills and relationships, which makes the younger Deku reevaluate his own path as a hero.
In the manga, Deku experiences various ups and downs. He not only becomes stronger physically but also matures emotionally as he takes on greater responsibilities. There are also many unexpected plot twists that shape his journey.
It could lead to a completely different character dynamic and story arc. Maybe she'd face different challenges and have a unique perspective on being a hero.
The main differences are in their expressions and some minor details of personality. In the manga, Deku might seem a bit more intense, while in the anime, he's sometimes presented a bit softer.
Well, obviously Deku in two forms - the younger and the older version are the main characters. The younger Deku is the one who is still growing and learning, while the older Deku has more experience.