Ultraman Dyna (ウルトラマンダイナ in Japanese) is a japanese tokusatsu TV show which aired between September 6, 1997 to August 29, 1998. Light-hearted sequel to Ultraman Tiga that takes place on the Neo Frontier of space. The series had 51 episodes.
Ultraman Dyna set seven years later in AD 2017, when humans are embarking on terra-forming Mars and other planets in what is known as the Age of the Neo Frontier. The series begins with the Neo Frontier being attacked by the Spheres, some UFOs that show up on occasion throughout the series. Asuka has just joined SuperGUTS and is in the middle of training maneuvers above Earth's atmosphere when they are attacked. He proves himself in battle, and can hold his own against ace pilot Ryoh. However, his ship is damaged and he ejects. He is then encountered by a shining light, Ultrman Dyna. Following that all-too-familiar pattern, Dyna merges with the bewildered Asuka. When the Spheres enter Mars' atmosphere and merge with the Martian rocks to form monsters, Asuka again participates in the battle, but when he finds himself in a pinch, he suddenly transforms into Ultraman Dyna. The members of Super GUTS quickly catch on that this is not Ultraman Tiga from seven years ago, but a new giant of light. (Wikipedia)