Yakuza 4 (Ryu Ga Gotoku 4) was released in Japan last year when we received Yakuza 3. Sega has done a tremendous job in localising Yakuza 4, everything that was missing in Yakuza 3 (hostess bars) is back in Yakuza 4. The only thing cut from Yakuza 4 is the AnswerxAnswer quiz mini game and the Japanese Intro with the song called 'Butterfly City' (licence).
In Yakuza 4 you play as four main characters, 3 new characters along with the 'Dragon of Dojima' Kiryu Kazuma. Shun Akiyama, the 'Lifeline of Kamurocho' who is a money-lender/loan shark. Taiga Saejima, a fugitive on death row who killed 18 men back in '85. And Masayoshi Tanimura the 'Parasite of Kamurocho', who is a cop that delivers his own brand of 'Justice'. Each character has a different fighting style, Akiyama is fast, Saejima is a powerhouse but slow, Tanimura relies on parries and technique and Kiryu is balanced (well he has been the main protagonist throughout the series, Yakuza fans know what techniques Kiryu has).
The story is the most important aspect of the Yakuza games. The story is much more darker than the Yakuza 3 storyline. If you did not like the Orphanage part of Yakuza 3 then you will probably like the starting in Yakuza 4 (although it is confusing). It doesn't have much emotional parts like Yakuza 3 did but there is a few heart warming scenes in the game. The storyline will probably take you around 25 hours or more to complete depending on what you are doing for example playing the mini games and doing a few sub-stories.
The leveling system has changed and is different compared to Yakuza 3. When your character levels up, the health and heat meter automatically upgrades but you get ability points, which you can spend on learning new moves for your character. The highest/maximum level for every character is level 20. You can also learn new moves by the returning revelations from Yakuza 3 (and Kenzan) and IF7-R which looks like a saiyan pod from Dragonball Z (IF7 was in Yakuza 3).
The mini games are back and better than ever. You can get easily distracted from the story by playing the mini games in Yakuza 4. You can play pool, bowling, table tennis (new), golf, gamble, fishing and more. There is online leaderboards for this game, you can check what rank you are with each mini game (I'm not sure if it's region or world wide ranks). You can create your own hostess with Akiyama, train a rookie fighter with Saejima (Hideo Kojima reference), stop criminals and resolve problems with the police scanner with Tanimura, or take on gang members with Kiryu.
The only issues I have with this game is dialogue, graphics and the map. The dialogue can annoy you if you just want to get on with the story (non playable characters mostly interrupt). The graphics have slightly been upgraded, but you get the same annoying graphical issues that were in Yakuza 3. Kamurocho is the main setting in each Yakuza game. In Yakuza 4, Kamurocho is the only setting (No Okinawa from Yakuza 3) but you get a underground mall, sewers, parking lot, docks and rooftops. I just knew most of Kamurocho from the back of my hand (because I played Yakuza 3 a lot).
Get this game if you are into Japanese games, especially if you are into RPGs. You get a good story, likable/ dislikeable characters and mini games plus sub-stories to distract you. The game is worth the money as you can probably put in around 100 hours into getting 100% overall (not including platinum trophy, you probably get a platinum trophy before attempting 100% overall in the game like Yakuza 3).