Izuku is going to have Ace and Sabo as brothers while during his time Shanks and Garp will have Luffy's past as well. I also decided to make Devil Fruits exist but they'll be extremely rare, so rare that they are nearly forgotten and people with Devil Fruit powers are just assumed to have really powerful Quirks. And as you read by the title Izuku will have Luffy's rubber-like abilities since he will eat the Gum-Gum Fruit, he'll also be given Gear 2nd, Gear 3rd, and Gear 4th as well as him being a master at Haki, but just like Devil Fruits Haki will be nearly forgotten. But it won't be until later in the story, you'll just have to keep on reading. There will also be some one piece characters in the story coming up and I will give the heroes bounty by the villains similar to one piece.

Now onto the harem

Ochako Uraraka

Tsuyu Asui

Momo Yaoyorozu

Nejire Hado

Mina Ashido

Kyoka Jirou

Vivi

Rebecca

Toru Hagakure

Himiko Toga