Blue Gender is a Japanese anime television series created by Ryōsuke Takahashi, the creator of Armored Trooper Votoms and Gasaraki, broadcast in Japan from 1999 to 2000 and spanning 26 episodes.

Blue Gender was animated by the Japanese studio AIC and distributed in the United States by Funimation - one of the company's first non-Dragon Ball licenses.

Blue Gender is set in the 2030s, in which Earth has been overrun by the Blue-alien insectoid creatures containing a newly evolved B-cell, that kill and harvest humans for food.

In 2009, Yuji Kaido is an average young adult male diagnosed with a serious disease (the "B-cells") and is put into cryogenic stasis until a cure is found.

Twenty-two years later, he is awakened in the midst of a raging war between armored soldiers and insectoid beings called the "Blue" which have overrun the Earth.

Standing orders for Marlene and the other troops are to consider any human survivors on the surface to be already dead, which greatly troubles Yuji.

On their journey, all of the soldiers are killed except for Marlene, causing Yuji to fall into a deep depression as he recognizes the destruction around him and his own inability to save those he cares about.

During their travel to Baikonur space base through the mountains, Yuji and Marlene start to develop a bond that softens her sharp edges.

However, just when she is going to self-detonate her Armored Shrike, Yuji, determined not to leave her behind, comes to her rescue with a team of reprogrammed automaton attack sentries.

When she does, she finds he has healed and is being trained to use a new specialized "sleeper"-specific Armour Shrike (AS) called the "Double Edge", a battlesuit that is much stronger than the originals used in the war against the Blue.

However, the battles begin to have a negative effect on Yuji, who has very little regard for human life and is completely obsessed with being better than Tony at killing the Blue.

After learning from Seno about a new migration pattern of the Blue, Yuji and Marlene take a group of volunteers and head to an area where a massive nest is located.

All around the world from former Blue Nests, long strings of coalescing energy ascends into Earth's atmosphere and form a ring.

"[6] Nerdgenic.com also gave the series a positive review, with their only criticisms being the main protagonist Yuji, and the slow progression of the plot.

Issac Cynova of THEM Anime Reviews was far more critical, and gave the series a rating of 2 out of 5 stars, stating that "Blue Gender is one of those titles that hooks you right from the beginning, but then just fails to deliver.