Like Words Worth, it's a hentai adaptation of a video game from Japanese eroge developer ELF. They've also had mainstream anime TV series made from their games, e.g. Elf-ban Kakyuusei, Raimuiro Senkitan and YU-NO. It's also quite good and far more tolerable than Words Worth. It's a hentai you wouldn't be embarrassed to be caught watching.

It's three unrelated stories, not a six-parter. They don't all even have a single protagonist. Takeru's the hero in eps.1-2, then his son Kakeru takes over in eps.3-6.

You could almost broadcast it on TV. Not every episode has a sex scene and everything's softcore, except briefly in the 1995 gaiden. Its two heroes aren't sex fiends, giving women lots of space and sometimes being downright gentlemen... although Takeru definitely appreciates all the nudity in ep.1 and Kakeru has sex with Princess Bianca to teach her a lesson in ep.4.

We only know of Takeru having sex with one girl, which might have been when Kakeru was conceived. He also doesn't back down from a job even on learning that all his predecessors got killed by Dragon Knights. Instead of saving his own skin, he just shrugs and gets on with what he'd promised to do.

Takeru's a skilled but unlucky adventurer who's more at risk from starvation from monsters. The Dragon Knights are a gang of lizardmen, minotaurs, etc. who've kidnapped the warriors from an amazon country and stolen their goddess's blessing. The amazons catch Takeru stealing food and are about to chuck him over the border when they remember a prophecy. "When darkened clouds are stripped of flowers and leaves out of season begin to change, the moon shall light our waking hours and the hero will come from the southern range." (The subtitles translated it in rhyme!) Can Takeru defeat the Dragon Knights?

It's quite a good comedy. "I know he looks pretty useless, but first impressions can be misleading." Even the evil overlord made me laugh, when he sneaked off with a comedy sound effect.

Takeru gets an amazon guide, Luna, who scolds Takeru for his responses to naked women... and then herself gets turned into a tiny pink dragon. She also seems more familiar with men than you'd expect from a country of women.

Disappointingly, Takeru hasn't settled down with Luna. (This is clearly set after the first OVA, which rules out the obvious fan theory workaround.) Then, once again, Takeru leaves at the end without taking further advantage of his good luck with this episode's girl, Jodi.

I'm confused by the title. Hadn't Takeru defeated all the Dragon Knights?

This one's more serious than its predecessor. Jodisu is a thief who's passing as a boy, but she gets captured by the baddies and given a nasty whipping. Even Shade's henchmen slink off awkwardly to avoid watching. There's also a forbidden drug with hentai effects that can drive its victims mad. This is the least memorable of its franchise's three instalments, but it's still a perfectly good, well told fantasy story.

...after which this was a shock. It's tragic and dramatic. Kakeru has been in prison for years after everyone in his village got turned to stone (yes, including Dad) and Kakeru's friends were killed by the demonic baddie Lucifon. Their deaths were traumatic. They were dropped into an abyss, with Kakeru's girlfriend Natasha deliberately falling when he tied to save her.

There's a way out, though. An elf called Marureene has a black stone that can send Kakeru back through time to change the past, on condition that he talks to her earlier self and persuades her to change her mind.

This plays out better than many serious SF stories I've seen with that kind of premise. Kakeru calls himself Edou and teams up with his younger self, which we're not expecting to end well for him. Young-Kakeru was the only survivor of the Lucifon encounter, after all. If Edou's history-changing mission fails, he'll die with everyone else. If it succeeds, he'll disappear. As early as the halfway point, Edou can look depressed and might say things to his younger self like "it's all up to you now, Kakeru". The battles are played for keeps. Heroes die. Allies can charge in too early, disrupt their own side's bombardments and get good people killed.

There are also Dragon Knights, but of a different kind to last time.

I was impressed. The 1991 episode is a witty fantasy comedy, albeit with gratuitous nudity, and an engaging story with likeable characters. The 1998 series is startling. The 1995 gaiden is perfectly okay. This one's worth a look.