Gakken Co., Ltd. (株式會社學習研究社, Kabushiki-gaisha Gakushū Kenkyū Sha)is a Japanese publishing company founded in 1947 by Hideto Furuoka, which also produces educational toys. Their annual sales is reported at ￥ 821 billion ($6.5 billion US).
Gakken is perhaps originally known for producing Denshi blocks and packaging them within electronic toy kits such as the Gakken EX-System, as far back as the 1970s. One of their original lines, the EX-150, was reissued in 2002, and was so popular as to inspire an expansion pack. - http://en.wikipedia.org/wiki/Gakken
Gakken is known in our circles for producing toys for the TV show Genesis Climber Mospeada, which went on to be adapted as Robotech, the Next Generation.