故事讲述了宇宙警备队新队员泽塔奥特曼为了成为保护地球的战士，成为了赛罗奥特们的徒弟，起初被师傅称只有三分之一的半吊子实力，后来在不断的战斗和其他奥特曼的教导下，成为了能够保卫和平的宇宙战士的故事

主人公泽塔奥特曼是一个新加入到宇宙警备队的新人，实力在众多奥特曼中并不出众。他的偶像是赛罗奥特曼，为了让自己变得更加强大，他开始拜师赛罗。起初赛罗对自己这个徒弟评价是，连半个英雄都抵不上。但是内心中却非常认可他的潜力，泽塔奥特曼拥有着用不仅的精力，起初在地球上，由于不熟悉地球文化，犯了很多的错误。不过他有着极其强烈的正义感和一颗想要保护世界和平的热情。后来泽塔奥特曼和人间体夏川遥辉一起合作，在地球上执行保护地球的任务。

The story tells that Ultraman Zeta, a new member of the Space Guard, became an apprentice of the Cyro Alts in order to become a warrior protecting the earth. It is said by the master that it is only one-third of half-strength, and later, under the constant fighting and the teaching of other Ultraman, it becomes a story of a space warrior who can defend peace

The protagonist Ultraman Zeta is a newcomer to the Space Guard, and his strength is not outstanding among the many Ultramans . His idol is Ultraman Zero. In order to make himself stronger, he began to learn from Zero. At first, Sai Luo's evaluation of his apprentice was that he was not even half a hero. But in his heart, he recognized his potential very much. Ultraman Zeta possessed unremitting energy. At first, he made many mistakes on the earth because he was not familiar with the earth's culture. However, he has an extremely strong sense of justice and a passion to protect world peace. Later, Ultraman Zeta and the human body Natsukawa Haruki cooperated to carry out the mission of protecting the earth on the earth.