According to the leaflet, the release date of this pocket game was 昭和５８年１０月１８日 (in the formal Japanese calendar notation), which means 18th of October 1983.
The slogan on the front page urges you to "Challenge the computer" (「コンピュータにチャレンジ」), which refers to the fact that you could play against a computer opponent.
The Computer Mah-jong Yakuman is the first game machine to feature a link cable, allowing two games to be hooked-up for four-player Mah-jong (2 human and 2 computer players)!
Two accessories were available for the Computer Mah-jong Yakuman: the aforementioned link cable, and an optional AC adapter (alternatively you could power it by means of 4 AA batteries).
The Computer Mah-jong Yakuman cost ¥16,800, for which it delivered a slick portable experience - aimed at 'the older gamer'. Still, a pretty hefty price tag if you compare it to the ¥14,800 retail price of a Nintendo Family Computer, released in July of the same year.
|Full brochure - front and back outer pages
It may seem strange that Nintendo released a game machine like the Computer Mah-jong Yakuman, which could only play a single type of game, three months after the launch of the versatile Famicom. But don't forget that around this time Nintendo was also still busy churning out the (mighty successful) Game & Watches. The Computer Mah-jong Yakuman should be seen as a Game & Watch for adults. Also, the initial response to the Family Computer was not phenomenal; it took some time for sales to take off (until they went into orbit after the release of Mario Bros.), so Nintendo rightly did not put all their eggs into one basket.
|Full brochure - left and right inside pages
For more information on the Computer Mah-jong Yakuman, check out this post.