Ozuma takes place in a future Earth where, due to an increase in temperature of the Sun, the Earth as we know it has dried up and turned into a harsh desert planet. The story follows Sam Coin, a young man that's part of a rag-tag band of sand pirates who dreams of one day catching an "Ozma": one of the legendary giant sand-whales. Along the way, he meets up with the mysterious Maya who's being chased by Theseus army. His act of rescuing her and bringing her onto their ship starts them on an adventure involving fanatical governments, pirates, cool ships and an earth shattering mystery - in other words, it's a typical Matsumoto story, except that it's set on a desert planet instead of in space.
Where series fits in the (or if it is even part of) Leiji Verse is as of yet unknown.
This anime provides examples of:
- Badass Cape: Worn by Captain Bainas, as is standard for badass ship captains in Matsumoto's works.
- On top of that, she also wears a Scarf of Asskicking.
- Belligerent Sexual Tension: Sam and Mimay, as much as you can get in Matsumoto's work anyway.
- Distaff Counterpart: Bainas is a combination of this to Captain Harlock as well as an Expy of Emeraldas from the same series.
- Also Dr. Luna for Dr. Zero, also from the Harlock shows. Both are medical officers who are never seen without a bottle of alcohol, both also take care of Mii-kun - the ships cat (based on Matsumoto's real life cat).
- Expy: The titular sand-whale, to Moby-Dick. See also Reused Character Design below.
- Grand Theft Me: Eventually, to be able to keep on living since cloned bodies no longer work, the people of Theseus start kidnapping natural born Naturas and stealing their bodies.
- Gido himself is an example, having taken over the body of Dick, Sam's older brother. This also leads to his HeelFace Turn at the very end, when getting injured in the head lets Dick back in control of his body.
- Hard-Drinking Party Girl: The ships medical officer, Dr. Luna. Possibly a Shout-Out to the perpetually drunk Dr. Zero, medical officer of the Arcadia.
- Hostage Situation: A rare case where it's the (supposedly) good guys who pull one: Bainas submerges her ship to escape Gido, and while taking Maya in it. Gido plants some under-sand tremor detector and prepare his ships to shoot at the slightest under-sand movement detected. Bainas turns off all the ships-machine to go silent. This makes the ship's interior as hot as oven since the AC is not functioning, and Maya's very weak body can barely endure the heat. This forces Gido to decide whether to abandon the chase without Maya, or wait until Bainas' crew surrender, possibly with a dead Maya on board. In the end Gido decides to let them go.
- Implied Love Interest: Captain Bainas responds in such a way every time she remembers Dick, that she thought very highly of him. And in the final scene with Gido where she questions whether he's Gido or Dick and he responds with the goodbye he gave her before he left, her eyes and voice pretty much say it all.
- Noodle People: In an elegant, refined way as is a staple of Matsumoto's art.
- Reused Character Design: A staple of Matsumoto's works.
- Sand Is Water: Substituting for Space Is an Ocean in Matsumoto's other works.
- Explained by the Bardanos (and other submersible ships and Ozma itself) being able to generate a field that makes sand act like water.
- Sand Worm: The titular Ozma (though it's more of a sand whale than a worm).
- Silent Running Mode: Bainas orders the Bardanos to shut down their main engines to avoid detection by the enemies passive sonar. However, this risks overheating the boat as it prevents them from dissipating heat.
- Techno Babble: There's lots of it, many of which are real naval terms, and the sand-submerge technology isn't entirely implausible.