One of the Choushin and the Assimilated Partner of Sasami.
In appearances she has made within the Tenchi Muyo franchise, Tsunami is portrayed to have a significance role with influencing events that play out throughout any continuity she appears in being in influential positions to do so.
Tsunami was created as a character of Masaki Kajishima's Tenchi Muyo anime, manga and novel franchise. There is no information about her character known during development of the series. Tsunami has appeared in anime and manga installments of the Tenchi OVA series, a manga spinoff of Tenchi Forever called Eternal Memory and Pretty Sammy. For anime adaptations, she was voiced by Chisa Yokoyama in Japanese. For English, she was voiced by Sherry Lynn for the OVA series and Lara Cody for the Pretty Sammy OVA series.
Due to their assimilation, Tsunami is physically similar to what Sasami would look like when she is an adult as she has the same long blue hair and melon pink colored eyes as the young Jurai princess.
Tsunami displays a courteous and formal demeanor when addressing others. In spite of her status as a goddess, she is supportive of allowing Sasami living her life as she fits and will step in to assist her in serious situations.
Tsunami is one of the Choushin, one of three nigh-omnipotent goddesses who created the very multiverse. It was her influence that allowed Jurai's influence in the universe to flourish as she created the Royal Trees used to power Juraian spaceships. Tsunami hoped to find the power of a higher being by having it reveal its power through someone born of the Juraian bloodline. Over 700 years ago, Tsunami saved the life of Sasami, who was dying from Ryoko's attack on Jurai, by assimilating with her thus giving Tsunami a human form. Tsunami was summoned by Sasami to combat Kagato and later explained her assimilation with Sasami to Ayeka and Tenchi. She was also summoned to prevent Z from killing Tenchi and sustaining control of Tenchi's power before it destroyed the universe.
Tsunami makes an appearance in the manga adaptation of Tenchi Forever called Eternal Memory. Sasami enters into her chamber while being persuaded by a girl named Izumi. Sasami sought Tsunami's power to learn of a means to save Tenchi from Haruna's world. Tsunami has Sasami reflect on her feelings for Tenchi and makes her realize that Tenchi must make the decision himself to be freed from Haruna's world. Despite this, the two do assimilate as they did in the OVAs and Sasami made use of Tsunami's power to allow the girls on Earth passage into Haruna's world to save Tenchi.
Tsunami is one of three successors chosen to be the queen of the magical land known as Juraihelm. Chosen to be the next in line as queen of Juraihelm, Tsunami had to choose a human from Earth to be her representative. She chose Sasami Kawai as her representative and gave her the power to transform into the magical girl, Pretty Sammy. Unlike her courteous and eloquent demeanor in the OVAs, Tsunami is more carefree and a bit ditzy in her behavior for both the OVA and TV series to Pretty Sammy as she is oblivious to Ramia's plans to sabotage Tsunami's chances of being queen and can be fooled rather easily by the comical villain.
As the creator of the known multiverse within the OVA continuity, Tsunami is one of the title's strongest beings being equaled in strength by her sisters and the Counter-Actor, while surpassed by Kami Tenchi. She is a nigh-omnipotent being capable of warping reality on a multiversal scale, existing in multiple dimensions and her very presence threatens the stability of the universe if she were to engage in combat.
As the origin of all Juraian ships, Tsunami is capable of taking on the form of a spaceship and existing simultaneously within its confines as its pilot. The spaceship can generate 10 Light Hawk Wings whose defenses are unrivaled by nearly any force within the known universe. It is capable of sub-space travel, manner transportation and generating laser-based weaponry that is potent enough as such to completely cripple the Soja.