Tokusatsu series produced by Tsuburaya Productions.
The series involves the titular Ultra race, a giant humanoid alien species who were tasked as peacekeeper around the universe and help to protect various planets (especially Earth) from kaiju threats.
The following tags implicate this tag: kaette_kita_ultraman, ultra_kaijuu_gijinka_keikaku, and ultraman_(1st_series) (learn more).