In America, the Transformers cartoon came to an end in 1987 with The Rebirth, a three part series which saw the debut of the Headmaster and Targetmaster characters. Whilst interest in Transformers had declined in America, in Japan the brand was still going strong, so much so that Takara (who own the Transformers brand in Japan) decided that instead of dubbing the American cartoon into Japanese as they had being doing, they would create their own series. The result of this was Transformers: The Headmasters, which aired between July 1987 and March 1988.
And the results are disappointing. The Headmasters has several major problems with it, one of the most blatant being how boring it is. Episodes often just amount to "bad guys want energy, good guys stop them", not helped that there is a entire arc involving Galvatron going to different planets to get energon. And then there are the characters, the boring, unlikable characters. Most of the Cybertron Headmasters are snobby jerks, and then the Cybertron Targetmasters appear and be even more snobby.
Some of the writing is terrible, such as Convoy being killed off in one episode, but then in the next one Broadcast is brought back to life -surely if the Cybertrons had this miracle technology that can bring the dead back, they'd use it for their leader? The real reason for this is because Broadcast had a new toy whilst Convoy did not, but still. And then there are other things -why is it that when the Destrons blow up their space bridge in this episode, the Cybertron space bridges -all of them, on different planets -blow up also? Why does Chromedome magically use a space bridge in this episode despite the fact they were all destroyed? And then later on in the same episode, Fortress and his ship are thrown into molten lava, only for this to magically revive him. It takes away all the tension and is downright stupid.
The animation is also hit and miss. Toei animated the entire series, and the first few episodes feature excellent visuals. But then there are several episodes with major coloring errors and lackluster animation. This improves towards the end of the series, and there are a few episodes which use a more detailed animation style, but I would have preferred it to have been kept more consistent throughout the series.
The Headmasters isn't unwatchable, but there is nothing remarkable about it and it is tough to recommend. It is clearly the worst out of the Japanese-exclusive series. It has a few decent moments -such as the brief appearance of old characters, Fortress Maximus appearing for the first time and some actual character development shown at the near end of the series -but I'd advise skipping it and going straight onto Super-God Masterforce.