Finland's mobile game developer Supercell was purchased by Japan's GungHo and SoftBank last year. Since then they were active for a Web ad and mobile ad of Clash of Clans and Hay Day in Japan. However, they began the notice of the real ad at Shibuya Station, Tokyo at last. You can watch this in Yamanote Line area of Shibuya Station until April 27.
In addition, they install a special booth in SoftBank Shop Shibuya from April 25 - May 30.
By the way, game conference OGC 2014 is held tomorrow in Akihabara, and Supercell CEO Ilkka Paananen performs a commemorative speech of the 10th anniversary of OGC.