---
title: "Grendizer, Getter Robo G, Great Mazinger: Decisive Battle! The Great Sea Monster"
year: 1976
canonical_url: "https://www.archytele.com/show/grendizer-getter-robo-g-great-mazinger-decisive-battle-the-great-sea-monster-1976"
media_type: "movie"
tmdb_id: 74623
imdb_id: null
status: "Released"
runtime_minutes: 31
community_rating: 6.0
vote_count: 0
content_rating: "Unrated"
---

# Grendizer, Getter Robo G, Great Mazinger: Decisive Battle! The Great Sea Monster (1976) — Television & Cinema Intelligence Dossier

> **Archytele Living Vault Canonical Record**: https://www.archytele.com/show/grendizer-getter-robo-g-great-mazinger-decisive-battle-the-great-sea-monster-1976

## Executive Summary & Cultural Positioning

Grendizer, Getter Robo G, Great Mazinger: Decisive Battle! The Great Sea Monster is an animated short film produced by Toei that premiered on July 18, 1976, in Japan. It functions as a crossover of three super robot anime: Grendizer, Getter Robo G, and Great Mazinger.

The story follows a giant sea monster named Dragonsaurus that emerges to terrorize the ocean depths. As Great Mazinger, Grendizer, and the Getter Robo G team combine their forces to fight the threat, the mission becomes more complicated after Dragonsaurus swallows up Boss Borot and advances toward Tokyo.

## The Hook & The Verdict

**The Hook**: "Super robot teams unite to battle a giant sea monster threatening Tokyo."

### Why Watch
- It features a crossover of three super robot anime: Grendizer, Getter Robo G, and Great Mazinger.
- Great Mazinger, Grendizer, and the Getter Robo G team join forces to combat the new threat.
- The plot escalates when Dragonsaurus swallows up Boss Borot and heads toward Tokyo.

### Caveats & Content Note
- It has a short runtime of only thirty-one minutes.
- Tone & Suitability: The film is an animated action and adventure short with a brief runtime.

**Micro-Themes & Vibe Matrix**: #giant-sea-monster, #super-robot-crossover, #animated-short-film, #tokyo-threat, #action-adventure

## Streaming Availability Matrix

Direct streaming licensing updates dynamically. Consult the live tracking interface at https://www.archytele.com/show/grendizer-getter-robo-g-great-mazinger-decisive-battle-the-great-sea-monster-1976#watch.

## Creative Credits

- **Directed by**: Masayuki Akehi
- **Networks / Studios**: Dynamic Planning, Toei Animation

## Key Cast Continuity

- **Akira Kamiya** as *Ryo Nagare*
- **Hiroya Ishimaru** as *Kôji Kabuto*
- **Keaton Yamada** as *Hayato Jin*
- **Kei Tomiyama** as *Daisuke Umon / Duke Fleed*
- **Keiichi Noda** as *Tetsuya Tsurugi*
- **Joji Yanami** as *Dr. Umon / Professor Yumi*
- **Rihoko Yoshida** as *Michiru Saotome*
- **Hiroshi Otake** as *Boss*
- **Kosei Tomita** as *Dr. Saotome*

## Canonical Frequently Asked Questions

### Q: Where can I stream Grendizer, Getter Robo G, Great Mazinger: Decisive Battle! The Great Sea Monster?
Streaming availability is not provided in the sources.

### Q: Is Grendizer, Getter Robo G, Great Mazinger: Decisive Battle! The Great Sea Monster worth watching?
It is an animated crossover featuring Grendizer, Getter Robo G, and Great Mazinger fighting a giant sea monster.

### Q: What is the binge duration for this film?
The film has a runtime of thirty-one minutes.

### Q: Are there essential episodes to watch beforehand?
The provided sources do not list essential episodes, as it is a standalone animated short film.

## Grounded Source Citations

- [Grendizer, Getter Robo G, Great Mazinger: Decisive Battle! The Great Sea Monster — The Movie Database (TMDB)](https://www.themoviedb.org/movie/74623)
- [Grendizer, Getter Robo G, Great Mazinger: Kessen! Daikaijuu…](https://en.wikipedia.org/wiki/Grendizer,_Getter_Robo_G,_Great_Mazinger:_Kessen%21_Daikaijuu)
- [Grendizer, Getter Robo G, Great Mazinger: Decisive Battle!](https://www.kinobox.cz/film/691589-grendizer-getter-robo-g-great-mazinger-decisive-battle-great-sea-beast)

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*Generated by Archytele Open Intelligence Systems. Data verified against TMDB and JustWatch APIs.*