Newsbrief: Today, Japanese publisher Marvelous announced (PDF link; Japanese) that it has acquired G-mode, the Japanese company best known in the West for its acquistion of a large number of IP from defunct publisher Data East in 2004. The news comes to us via Silicon Era.
Data East, of course, was the creator of classic arcade games like BurgerTime, Magical Drop, and Fighter's History. More recently, G-mode had merged with a Japanese studio called ONE-UP in 2006 and concentrated on mobile game development, lately including a game based on Square Enix's anime and manga IP Soul Eater.
G-mode had licensed its classic IP to Western partners in the past, and also put out Data East games on Nintendo's Virtual Console service for download. You can find a list of the G-mode-owned Data East IP on Wikipedia.