If you're looking for manga similar to Fischer's x One Piece, you might like these titles.
When Mr. Satan miraculously becomes king of his own country, there’s only one explanation: someone must have made his dream come true! And since it is said, that the day after a wish is granted, a very special event takes place, nobody wants to miss what happens next. As Sanji and Master Roshi wrestle with the decision of whether to do their duty and fight crime, or head towards a bevy of beautiful women, Luffy hitches a ride with Goku. However with Zoro’s terrible sense of direction leading him and Piccolo round in circles, and Buggy teaming up with Pilaf in the hopes of achieving world domination, will everybody be able to make it to their destination on time?
After Sena comes home from school one day, he finds a mysterious golden Nintendo DS lying in the middle of the floor. Deciding that it couldn’t hurt, he immediately begins playing Jump Super Stars only to be sucked into the game himself! As he literally drops into ‘Jump World’ he discovers that Dr. Mashirito has kidnapped a hostage and now, alongside the likes of Naruto, Luffy and even Bobobo bobo, Sena must try and rescue the helpless Mamori and find a way to return to the real world.