The OVA branch of the Tenchi Muyo! franchise may not hold a candle to several other major titles in terms of raw episode count, but with releases now spanning 28 years it is easily one of the most enduring of all anime series. This installment, consisting of four roughly half-hour-long episodes, was released one episode at a time from late 2016 through mid-2017 and is only now finally becoming available in English via Crunchyroll. (Episode 1 of Season 5 has also debuted on Crunchyroll, but Season 5 will be reviewed separately.) It is absolutely not an entry point for franchise newcomers, nor is it suitable even for casual franchise fans. To fully understand who everyone is and what all they are talking about, a viewer must be comprehensively familiar with all previous OVAs (especially season 3) and Tenchi Muyo GXP at the very least, and being familiar with Tenchi Muyo! War on Geminar is recommended. In fact, this season is effectively part of the backstory for War on Geminar.

Noboyuki's marriage to his longtime assistant Rea is briefly shown in season 3 of the OVAs, but episodes 1-3 of this installment, which take place during episode 7 of season 3 (after the point where the truth about Tenchi's mother is revealed), give the full details about the preparations for, and lead-up to, the marriage ceremony. A lot of this involves a plethora of characters from GXP and previous OVAs popping up and talking about other characters, with little to no reminders about who these characters are and how they are related; I heartily recommend having a Wiki page for the franchise open while watching this, especially if you have not watched some of this content recently. A lot of the content of these three episodes is quite banal, with characters discussing the personality quirks of one character or another, extensive matchmaking discussions, separate gatherings of the Masaki men and women on the eve of the wedding, and so forth.

However, there are two events of greater significance prior to the wedding. One involves Minaho from GXP, Kiyone's older sister (and thus Tenchi's aunt) finally meeting the grown-up Tenchi and spending a whole day and night with him and Ryo-Ohki. The other – and much more consequential – one is Rea's admission about her past during a group bathing session. In that scene the writing finally explains not only how she came to live at Katushiro's household but also where she originally came from. Without getting too much into spoilers, this is where the Geminar connection comes in, and that revelation (and ensuing investigation by Washu) rumbles to the core of War on Geminar, to the point that some things which seemed conveniently coincidental in that series are now shown to not be coincidences at all. The implications are staggering.

Episode 4, by comparison, finally moves the story past the events of season 3, beginning with the birth of Kenshi (the protagonist from War on Geminar) and then flashing forward several years. It primarily focuses on discussions over how best to prepare Kenshi for an inevitable eventual trip over to Geminar, in including revealing that Kenshi being a jack-of-all-trades on Geminar was something that was planned by the women behind him rather than a storytelling convenience, even if Kenshi did not realize it himself. One of the jokes here is that the planning for this involves an assemblage of women so prominent that they could collectively make the universe tremble, and yet they all wind up hanging out in a variety of playful venues, including one where they all lounge in sleepwear in a venue littered with giant plushies. The episode also confirms that Seina's marriage that was supposed to take place at the end of GXP did, indeed, finally happen properly.

These episodes often have a slice-of-life feel to them despite the powerful and prominent characters involved. Touches of the humor that the franchise has always been known for can be found here and there, but they feel restrained; the slapstick nature of earlier installments in the franchise is largely absent. No action elements will be found here, either, nor any of the familiar squabbling between Aeka and Ryoko; both are disappointingly calm during all of this, with Aeka in particular almost fading into the background. That may be because the only point at which Tenchi is the center of events is during his meeting with Minaho, as the rest of the time events concentrate on either Noboyuki and Rea or Kenshi. Because of this, the harem elements also largely fade into the background. The two constants with earlier content are the role of Ryo-Ohki as mascot and the penchant for fan service. Though the latter is restricted to two scenes, these do include actual and near-nudity as well as sexy shots of most of the OVA branches' major female characters.

This season is also notable for the artistic shift. Studio AIC is still listed as the primary production team, but the director and character designer are new to those positions and that results in a somewhat different visual aesthetic. This can be seen most prominently in several of the characters (especially Tenchi and Aeka) looking distinctly older compared to season 3 and others having more stable and refined designs. Ship designs also look sharper. In general, this is one of the higher-end installments of the whole franchise in terms of art and animation quality, though with no action element the animation is not challenged much. This season also accomplishes the critical task of getting Ryo-Ohki's cute factor right.

The musical score also offers a significant improvement. I was quite critical of the musical score in my reviews of season 3's releases, but this season has Ryo Sakai (the Kino's Journey franchise) as the new music director, and that makes a big difference. While nothing much about the varied musical selections stand out, they are at least reliable at supporting the proper tone for each side, whether it be sexy jazz for the big fan service scene in episode 4, gentler piano numbers for more somber moments or dramatic orchestration for bigger events. Each episode has its own opening and ending themes (though the opening themes usually play over events at the beginning of each episode) and these are also all perfectly serviceable numbers.

An English dub for this season is not available at the time of this writing. Among the Japanese cast, most return from earliest installments in the franchise. The most significant replacement is Ken Uo taking over the role of Katsuhito from original seiyuu Takeshi Aono, who passed away in 2012, but you will have to listen very closely to notice any difference.

On the whole, this installment lacks the verve of the franchise at its most lively. It is seemingly content with its storyline having enough established content that the series can afford to spend most of two hours of animation on downtime activities. Hence these four episodes function more as clean-up and connective tissue than plot driver, in the process both settling some earlier issues and setting up for War on Geminar. Understand that going in and this makes for a mostly-satisfying continuation of the OVA branch of the franchise.