Uchuu Kaizoku Captain Herlock

A charismatic, battle-scarred leader builds a force of like-minded “true men” who free themselves from their previous standing in society to gain freedom and fight for what they believe in. They end up fighting together against another species who had caused them hardship in the past. The anime also have a focus on romanticising certain traits and ideologies associated with masculinity, such as the desire for freedom and leading others in a single-minded battle. 

Though following different settings (Captain Harlock being set in a futuristic setting in space and Saiyuuki being set in a semi-fantasy setting) the feeling of adventure in both is undeniable. You grow an attachment to the protagonists almost immediately and can't help but support them even if their situations seem ridiculous. The antagonists are, in their own way, sympathetic. Both series' also have a habit of recreating themselves in sequels and so it feels like watching a different series with the same characters which can allow you to fall for the characters again in a whole new setting. 

They depict a gruff, black-cloaked, scar-faced man and his thrilling life as an outcast from the law. Appearances aside, he has a strong moral code and sense of justice that inspires people that he meets and encourages them to pursue their dreams. The protagonist dislikes the greedy bigwigs who plague the medical society and government, and makes a point of giving them a hard time through their extra-legal endeavours. The protagonist also acts as the Guardian and father figure to a little girl who he is not related to by blood. 

A futuristic Earth has become blinded by times of peace and plenitude and become slack and leisurely, causing them to ignore an alien military force coming from outer space to invade them. A lone captain gathers a crew and leaves Earth as an outlaw to protect his homeworld. 

A space outlaw that has a scar over his face. Also, there's an evil on Earth that needs to be defeated! There's also pretty neat aliens in both. 

Retro anime starring an intense and hot-blooded space pirate who is feared by some and idolized by others. They have interesting sci-fi worldbuilding with plenty of cool gadgets, alien lifeforms, and fictional locations on other planets. The protagonists have a unique and mysterious space ship that they was build for them by an old friend, and they are assisted by a kind of machine-like being during their adventures. 

Same Universe and feeling, both are dramatic and idealist stories about War, Drama, Aliens and discrimination. 

Both are amazing space opera and I enjoy listening to the Yamato opening every time. You'd be really surprised how similar both are. 

Harlock and his crew are practically banned from Earth while they fight to protect it from an alien race called the Mazone, which resemble beautiful women in appearance. In Ideon the group who discover the "Solo Ship" and the Ideon end up being pushed away from their homeworld as well, with nowhere to run while being chased by the mysterious Buff Clan that resemble humans themselves. In both shows, the casts home is ... their spaceship, with nowhere else to go. If you can appreciate old art and animation it's easy to say both shows still look great to this day, with the exception of Ideon's recurring stock footage here and there. The Harlock series has better pacing and a much more likeable and developed cast all around, while Ideon is strikingly a bit more darker in tone and very desperate in nature. Both have incredibly impressive soundtracks, orchestrated and all. By the end of these two shows you yourself might be out of breath, as you'll feel like you went through these huge adventures personally. Typical of Tomino stuff Ideon is a little quirkier at times and has mecha, but overall the show is far more space drama than some of his other works. Overall, both have a lot of similar themes and ideas, with very different styles and executions in terms of writing/directing. But in the end these are two amazing, action packed, and adventure filled classic space dramas. And please note: Be Invoked IS the ending to Ideon. Episode 39 is just a sampler. read more 

Very similar strong-willed main characters who fight for what they believe in.  

Space battles in massive ships. Space Pirate Captain Harlock is one of the many sources of TTGL and Simon's design in the final part is actually inspired directly by Harlock. It is a lot of fun and great to watch and note the similarities with today's animes. Harlock was (and still is) a very influential anime. 

Both have the pirate romance in it's true sense. People pursued by the world government put pirate flags on their ships and sail freely across the seas, be it with water or stars, and try to do what's right. Crew members of both Luffy and Herlock tend to have sad backstories, related to the enemies the crews fight. 

These two series are both amazing space operas, but not only are both made by Matsumoto, Leiji, but the setting as well is quite similar, the feeling you get of the atmosphere from both space battleships the Arcadia and the Yamato sure make up for an amazing ride of an intense story! So if you love space related anime and the work of Leiji then these anime series are definitely for you!  

Set in the same universe.