Tenchi Muyou! GXP: Paradise Shidou-hen

This is great, but like everything in the mainline Tenchi continuity over the last 10 years, it's aimed at hardcore fans that remember everything and makes no attempt to hold your hand or get you caught up. Casuals BTFO, and that's the way we like it. In order understand everything you are seeing you need to have decent recall on all of these:

Tenchi OVA 1-5
GXP NOVELS (the GXP anime is officially non-cannon and considered bad fanfiction botched by IRL Nabeshin from Excel Saga, the books only exist because Nabeshin's "changes"/removing half of the story for NB jokes pissed Kajishima off something fierce and he only ... got more mad as time went on)
Dual Parallel Runrun Monogatari (very important, this is beginning of the Tenchi timeline and plays a big part in both the GXP novels and Shidou-hen, find my translation on my blog)
Space Ofera Agga Ruter (GXP is the sequel to Agga Ruter's story, I did subs for this one too, the eroge is also canon but was never translated)

There are references to Photon and Isekai no Seikishi Monogatari, but having a basic familiarity with the premise is sufficient.

There is a time skip between the most recent GXP book (vol.18 as I write this) and the OVA. Fortunately, the missing big picture details are easy enough to figure out. To further complicate things, the Paradise Shidou-hen novel is considered the first draft and the anime is canon.

With aaaaaaaaalll of that out of the way.......if you're still here, and you liked OVA4 and OVA5, you'll like this too. Every episode is incredibly dense. You can tell Kajishima killed himself to cram everything into 6 episodes. It could easily be twice as long. It probably should be 12-13 episodes, but nobody has had the balls to do an OVA series that long since the 90s.

Somehow it can feel slow with no BGM (the budget clearly went in to the animation and voice talent) despite its breakneck pace. The story is always progressing and building on something that set it up somewhere else in the timeline. There is zero downtime. Look away for a minute and you will miss something important. Stylistically it's similar to OVA4 and OVA5 with dense dialogue that has multiple layers of subtext.

Without spoiling anything, this delivers on a lot of things that are set up in the GXP novels that are not in the anime. Things about Tsukiko that were cut, major plot points that are only introduced in the last 3 books are heavily referenced, characters that didn't exist in the anime at all are featured, how there are four more *spoiler redacted*...you get the idea. Kajishima knows what the paying customer wants and delivers it in spades.

Paradise War takes place immediately after this OVA so those books finally make sense.

tldr strongly recommended for real fans but casuals have some homework to do first

This series is for experts of Tenchi lore only. I watched it and despite having seen all the Tenchi anime set before it, it was still very confusing. Even if you have seen all the OVAs and the spin-off GXP, you will be hit with countless relatives and aliens you did not see introduced properly. As the series begins, Seina returns to Earth with a lot of women who did not appear in the GXP anime. Characters from the TV series generally do not appear much in this besides Seina. The reason for this is that this is a sequel to Japan only Tenchi novels ... which introduce yet another group of harem wives. The purpose of this OVA is to set up other preexisting Tenchi books and OVAs, by explaining how Seina came to create an island spaceship inhabited by lots of pirate women. However it is not properly explained who the new human arriving at the end of the anime is, so that leaves anyone who hasn’t read books in the Paradise War series confused. It is also not really explained why Seto decided to settle lots of pirates on this island, or even why the island needs to exist to begin with. No one on the island seems to be aware of the reasons for her plans. They simply go along with the committee decisions from prior OVAs and books. There is very little in the way of action in this OVA. The humor is all based on one of the new wives being a perverted otaku who died and was reincarnated as an alien. She is a very obnoxious character who is always screaming and getting beat up by the other characters. There is no chemistry between Seina and any of the other wives, but especially not her. The reason they are married is not explained here, but it seems to be because she was a package polygamy with some hot elf girl that appears briefly in the last couple of episodes. The main romance in this OVA is between Seina and his best friend/wife’s mom. In the first episode she tries to sleep with him and while we never see it; a later conversation implies she slept with him off screen. This plot is creepy, but par for the course with Tenchi’s insane incest and age gap romances. After the first episode or two, the infatuation between those two is put secondary behind her gaining magical powers. The first thing she does upon getting magical powers is create doubles of herself to go kiss Seina while the guards are sleeping. Seina never seems comfortable or consenting to any of the girls’ romantic advances, but married them all anyway for reasons not explained here. Another source of confusion is that many of the characters change into Cabbits, and it is hard to tell them apart when the Cabbits get into a marathon gossip session about Seina.