On 17th October, Akihabara, we played experimented in AR tag again. Only 2 people were in the first, most of us were new players in this second time.

Makoto (UEI) developed an AR camera app for this tag game and we used it experimentally.  

As you can see, players and It are shown as blue circle and the building of Yodobashi-camera is shown as red one. The lengths to them are also indicated.  The app was better than expected and we could find the place and direction to It easily.

A camera pass-through AR makes invisible information visible like this app indicates the places of the players, so it has a similar effect to the application of optical camouflage innovated by Mr Inami.

Also we played the game in much narrower area, Kanda-izumichou.  The area is narrow and complicated. So we utilized such uniqueness of the map and made a strategy. We pretended to gather in the same place by pushing repeatedly “search” button.  When it came near, we run away at the same time to different directions.


However, team of It also made their strategy. They shut out our ways and attached us from bot sides!

The man in leather jacket and the girl were It…! 

Though our strategy was failed unfortunately, but it was really thrilling time as that was the first intellectual play in these AR tag games! 

The server for AR tag app (the same one as before) seemed to be enhanced and fixed so we could use it more smoothly.

Interesting time passed really quickly and our iPhones’ batteries were also consumed so we stopped playing after 4 games has been done. This time was really enjoyable as the first.

Thanks so much everyone for coming! 

Oh! I should not forget to tell a great contribution by Mr Itoh. His live camera recorded how we play the game.  Check it out from here!


I suppose that Akihabara is well known as digital city in Tokyo. But do you know that on 12th October, some “adults” gathered there to play tag!!

Of course, it is unusual tag, it’s a “digital” tag using iPhone app for the play (currently available only in Japanese).

iPhone app for tag by Kunihiro Takedomi

iPhone app for tag by Kunihiro Takedomi


The map monitored by tag radar

Your current location is shown at the centre of the map. Players caught by app’s radar are shown as green points, though it is unsure they are It or not. The player can know the direction to the green points on the upper left of the screen.

When a player is trapped by virtual bomb of It

When a player is trapped by virtual bomb of It

It can leave a virtual bomb at its current place. If other players pass there, the location of the player is informed to It for 5 minutes. So the 5 minutes becomes hellish time for the player!

After got the app, shi3z became to try it really and 12 hours before the play, shi3z called for people to play with in Akihabara. On the day of tag, 2 pm, 18 free curious people gathered in front of Yodobashi-Akiba.

AR tag players

AR tag players

The players wore blue tape on their right arms so that players can distinguish the players from other people.

The followings are the rule of the tag.

  • Don’t trouble other people. (It was national holiday and many people were there!)
  • Don’t run.
  • When It catches a player, both It and the caught player will be It.
  • Don’t enter buildings. But passing under piloti is OK.
  • Follow the traffic rules as usual.
  • Time limit: 30 minutes.
  • It starts to play 5 minutes after others.

Thought the server of the app seemed to be not good and we couldn’t access to the map or use chat system at the beginning, we played tag 3 times.  From the second, It could remove their blue tapes to disguise them as usual passengers.

It looks for pray...

It looks for prey...

found preys!

found preys!

Oh, no, caught!

Oh, no, caught!

Radar in the tag

Radar in the tag

We could use the radar sometimes during the plays.  We found that the radar is a kind of sonar to roughly know the places of targets. The app doesn’t  distinguish It and other players. Though the system make the game more thrilling in a sense, we need another one to distinguish them.

We have done exciting 3 tag plays peacefully.  The official event will be taken place on 24th October. We hope the server will be fixed and system will work properly. But anyway, it was really nice time to play such a technological tag. Thank you players for coming!! When shall we meet up for the next?