This is a Japanese STB Tatekan Poster (20" x 58") for the 1974 Japanese theatrical release for a "Toei Manga Festival" (Toei Manga Matsuri). The Toei Cartoon Festival (東映まんがまつり, Tōei Manga Matsuri) is a festival established by Toei Animation in 1967 as a way to showcase their popular children's series as theatrical films during seasonal breaks in the school year (spring vacation, summer vacation, and winter vacation).

The poster showcases a diverse lineup of popular 1970s media:

Mazinger Z vs. The Great General of Darkness (Mazinger Z tai Ankoku Daishōgun): The primary focus, featuring the iconic giant robot Mazinger Z facing off against the Great General of Darkness.

The Adventures of the Finger 5 (Finger 5 no Daibōken): A musical adventure film featuring the popular Japanese pop group Finger 5, who were a sensation at the time.

Kamen Rider X: Five Riders vs. King Dark: A tokusatsu film featuring the five original Kamen Riders battling the giant King Dark.

Inazuman: A live-action superhero series created by Shotaro Ishinomori.

Getter Robo: The classic "combining" mecha series.

Majokko Megu-chan: A "magical girl" anime series featured at the bottom of the poster.