Well, interesting to say, I have never played this game's predecessor, Jump Super Stars, as I was told the second game had much more features to offer. And believe it or not, despite there being no official English release, I found this game on the shelves of an American store.
So now we move onto the game itself. Before starting, I should mention this game was made by the big mother-you know what of videogames, Nintendo. Yes. Nintendo, the same exact company that made Super Mario and The Legend of Zelda worked on this game, But they only published it. The real developers were Ganbarion, more famous for the boat-load of their many One Piece games.
And, we get to what the game actually contains. As stated by the back of the game's package, it has 41 Weekly Shonen Jump series and a total of over 300 characters. At first, I can guarantee you would probably be thinking that this game has over 300 playable characters. But unfortunately, only 27 of these represented series actually contain at least one playable character, and if you were to add all of then up, the game has only around 50 characters you can actually control. I consider that a major disappointment, seeing as only one-sixth of the characters can be controlled by the player. (Nearly) Everyone else only appears as "Support characters" that you can call in for a short time to assist you during battle. At least you can play as classic Jump heroes like Goku, Ichigo, Luffy, and the dreaded Naruto. At least the good thing is, you can have everyone beat the living s#$@ out of Naruto, and enjoy it 100% of the time.
Now, we go onto the game's main story. From all the information I'm aware of, from my first playthrough (be warned, I am going to spoil a bit of the plot here), there is a land far away in space, known as the Jump World, where all the characters and their respective series' universes reside, until a mysterious character, later revealed near the end of the game as Dr. Mashirito, the evil mad scientist of Akira Toriyama's Dr. Slump, has shot all of the series deep into space, and sent the Jump World plummeting down a black hole (the Jump Blackhole to be precise.). Five lucky survivors, which consist of Son Goku (Dragon Ball), Gintoki Sakata (Gin Tama), Monkey D. Luffy (One Piece), Toru Muhyo (Muhyo & Roji's Bureau of Supernatural Investigation), and *sigh...* Naruto Uzumaki (Naruto), jump out of the Jump World as it is sucked into the black hole. The Jump Pirate (the name I give to the floating pirate head, the mascot of Weekly Shonen Jump) finds these five characters, and sends them to Earth (and a nearby asteroid) to train for their big adventure. As you advance further through the game, you'll encounter other worlds (located in the Jump Space, Jump Galaxy, and Jump Blackhole), recruit other characters that decide to help you on your journey, and soon, face the dreaded Doctor.
The gameplay first begins with you assembling a deck made up of "koma" (the Japanese word for Panel.), which is generally the team you will bring into the different battles, which consist of Battle (the characters you control), Support (the characters you can summon to assist you), and Help (characters that "attach" to Battle Komas to boost their power or give them new abilities, like a triple jump or wall jump. After your team is ready, your are sent into a page of Weekly Shonen Jump to fight one to three other teams that have one simple goal: Making sure you don't come out alive. If you win (in Story mode, that is), you will receive additional Komas and gems (the general currency of the game, consisting of Rubies, Topazes, Emeralds, Sapphires, Amethysts, and Diamonds, the last 3 being harder to find than the first.), which you use to upgrade the characters you receive, unlocking new Support and Battle Komas, as well as a couple other bonus content here and there, stuff you can (hopefully) enjoy, even without understanding Japanese.
Now comes the flaws. Yea, Every game is bound to have some sort of minor/major flaws, and this definitely has a few. Obviously, the game does not exist in any language other than Japanese (although I heard an un-official English translation patch was released a while ago), you probably have a bit of trouble navigating through the menus and beating the different missions without using a online walkthrough. But after a while, you'll begin to get used to the menus, you can get through them with little to no problem. Second, is the fighting themselves. I must ask this, Why doesn't this game have combo attacks that involve multiple pushes of the buttons to perform different attacks? I don't know why this game would lack a common feature in fighting games, but I have absolutely nothing to do about it. I can't really find anything else that pisses me off for now, so I'll stop here. (other than the fact I must address there are no alternative colors when two players control the same character.)
In conclusion, I don't recommended Jump Ultimate Stars that much to anyone that doesn't like Shonen Jump and/or fighting games in general, but if you can somehow find a copy of it, whenever it be online or in a retail store, I'd say check out. Otherwise, stay away.
Jump Ultimate Stars receives a 8.7/10.