One of Nintendo’s best new franchises is little known outside the US, and that’s cause, until now, it hadn’t had a release date for anywhere outside of Japan. Called the “Brain Training” series in Japan, these two titles charge you with doing mathematics, analysis, and memorization, as well as the ever-popular (in Japan) sudoku puzzles, and they are based on the works of neuroscientist Professor Ryuta Kawashima and use the abilities of the DS to full effect. 
The games have been extremely popular in Japan, matter a fact, they were among the top-selling titles of 2005 in Japan across all platforms. They will now be heading to the US with new names: Brain Age: Train Your Brain in Minutes A Da and Big Brain Academy. The first title will be released on April 17 and the latter on May 30th.
So look forward to giving that unused muscle of yours quite the workout via your game system in a couple months!