The wait is over for Pokemon Go fans in Japan.

The Japanese launch of the game on Friday morning included its first partnership with an outside company: fast-food giant McDonald's.

Within four hours of its launch, Pokemon Go was already the most downloaded app in Japan, the country of the character's birth, where it is expected to be a huge hit. Fans had been eagerly awaiting its release since it first came out more than two weeks ago in Australia, New Zealand and the United States, and then spread to become a blockbuster hit in more than 20 countries, including Canada.

"The best part is that I just got the first three [characters]. I felt like, 'Yes!' " university student Shuta Saito said in Tokyo's Akihabara district, a popular spot for fans of animation and games.

One of the Japanese creators of the augmented reality game apologized for the delay in an online video with the American head of Niantic Inc., the company that developed the app.

"To everyone in Japan: I am sorry to make you wait for so long," said Jyunichi Masuda, the head of development at Game Freak Inc., the developer of the original Pokemon game. "Pokemon Go can now be played in Japan."

In the game, players search for digital creatures that pop up on smartphone screens as they move through real-world locations. The game's success has sent the stock price of Nintendo Co. soaring. The Japanese game maker, in partnership with Game Freak, released the original Pokemon game in the mid-1990s, and owns the trademarks to all the game's characters.

Japan Pokemon Go Safety Tips

Japan's National Centre of Incident Readiness and Strategy for Cybersecurity put out this flyer with safety tips for Pokemon Go players. (Associated Press)

The launch in Japan includes a tie-up with McDonald's Japan that is seen as a potential expansion of the game's revenue base beyond the sale of in-app purchases.

Financial details have not been disclosed, but McDonald's said that about 400 of its 2,900 restaurants in the country are designated as "gyms" where players can battle on their smartphones. The other 2,500 are "Pokestops," where players can get "Poke Balls" and other items they need to play the game.

Because the game uses GPS, it can drive potential customers to a store in a way that other games cannot. "They are adding a new way to make money through mobile games by virtue of the GPS element in the game, and I think this deal is just the first of many to come," said Serkan Toto, a Tokyo-based games industry consultant.

Pokemon Go is already the top grossing app for in-app purchases in every market where it's been launched, Toto said, and the McDonald's deal "will constitute a second revenue stream for Niantic that other games cannot possibly have for systemic reasons." 

Keito Sato, 17, walking with school friends in Tokyo's Roppongi area, said he's been playing since he learned about the game's release via Twitter. He was hoping to test his skills in a battle at a McDonald's, but realized he had not reached a sufficient level to do so.

NINTENDO POKEMON launches in JAPAN

Pokemon Go players were roaming the streets of Tokyo's crowded shopping districts Friday, playing the mobile augmented reality game. Shares of the companies behind the game have surged due to its popularity. (Toru Hanai/Reuters)

As anticipation built toward the Japan release earlier this week, the government issued nine safety-related rules for Pokemon Go players to follow. The guidelines include cautions to protect personal information, be aware of fake apps that might contain malware, not enter dangerous areas and be on guard for heatstroke.  

Niantic CEO John Hanke asked users to play with care.

"When you go out to play, keep your head up, look around, enjoy the world around you and be safe," he said in the video message.

Nintendo's stock has surged since the game's release earlier this month, with its shares on the Tokyo Stock Exchange doubling between July 7 and earlier this week. They have since given back a bit of those gains.

Shares of McDonald's Japan were up four per cent Friday in Tokyo trading.  

With files from Reuters