AIKa ZERO

A Russo-Japanese War veteran partners with an Ainu girl to find a treasure stolen from her people, but they’re not the only ones pursuing the gold.

The story takes place in Japan in the early 21st century, in an alternate reality where the Tokugawa Shogunate has remained in power. In this reality, student councils are tasked with oppressing schools. Yagyuu Muneakira is a high school student who rebels against his student council with the help of girls who've had the names of famous samurai heroes passed on to them.

Earth faces an unprecedented threat from an invasion by the mysterious Kiseichuu. The Kiseichuu feed on human sexual energy, also known as “H-energy,” and weaken the human population. High school student Retto Enjo is a member of the hero group HxEROS, who fight together to save the earth from the Kiseichuu.

Struggling yet brilliant, 19-year-old Minato Sahashi has failed his college entrance exams for the second time, resulting in him being regarded as worthless by those around him. However, the course of his seemingly bleak future is altered dramatically when a beautiful, supernatural woman falls from the sky and into his life. That woman, Musubi, is a "Sekirei," an extraterrestrial with extraordinary abilities. Recognizing the potential of the Ashikabi gene within Minato, Musubi kisses him, initiating a bond between the two of them. This drags him into the high-stakes world of the Sekirei, where he and his new partner must compete against others in a battle for survival called the "Sekirei Plan." However, unbeknownst to the contestants, there is far more at risk that what the competition initially entailed. Manga series by Sakurako Gokurakuin.