
Akira Asagumo
main character


Invited to Nazi Germany during World War II, Dr. Asagumo is asked by Hitler to collaborate with him on the research of the new weapon "Big X". Concerned about the possible effects of the completion of Big X, Dr. Asagumo intentionally delays the progress of the research, conspiring with his co-researcher, the devious Dr. Engel. Immediately before Germany is defeated by the Allies, Dr. Asagumo implants a card inscribed with the secret of Big X in his son, Shigeru, and is then shot to death by the German army. Twenty years later, the card is discovered in the body of Shigeru, who is then living in Tokyo. Soon, an organization claiming alliance with the Nazis appears, steals the card, and completes the Big X project. Dr. Engel's grandson has joined the Nazi Alliance. The completed Big X is then revealed to be a drug that can expand the human body without limitation. Recovering Big X from the enemy, Shigeru's son Akira fearlessly challenges the Nazi Alliance and Hans Engel, who are plotting to conquer the world. Note: Most of the series is lost media. Only episodes 1, 11, 12 & 40-59 are known to still exist.
Only if you enjoy action and sci-fi, especially stories with shounen, historical, achromatic.
Reception is lukewarm: 52/100 on AniList, with 39% of 121 ratings at 8/10 or higher.
31.1% of viewers drop it before the end, more than most, so give it a few episodes to see if it clicks.
At roughly 24 h 35 min in total, it is a long commitment — about 4 weeks at an hour a day.
A streaming link is not listed for this title yet.
59 episodes are listed.
Theme data from AnimeThemes.moe.
Big X has 59 episodes of about 25 minutes each, roughly 24 h 35 min in total.
About 24 h 35 min back to back. At two episodes a day it takes 30 days; at one hour a day, about 25 days.
Yes. Big X has finished airing — the final episode aired September 27, 1965.
No sequel is listed for Big X as of October 2026. You can continue the story in the original manga.
Yes. Big X adapts the manga by Osamu Tezuka.
The opening, "Big X", is performed by Kamitakada Shounen Gasshoudan.