In Edo period Japan (1603 to 1868), a strange new disease called the Redface Pox has begun to prey on the country's men. Within eighty years of the first outbreak, the male population has fallen to a quarter of the total female population. Women have taken on all the roles traditionally granted to men, even that of the Shogun. The men, precious providers of life, are carefully protected and the most beautiful of the men are sent to serve in the Shogun's Inner Chambers.

When Kanako Miyamae transferred to a new all-girls school, she hoped to find true love. What she found instead was the beautiful Mariya Shidou, a charming classmate Kanako met on her first day. But Mariya has one flaw: she is actually a cross-dressing boy! After discovering Mariya's secret and becoming stuck with him as her roommate, Kanako's life has become a series of misfortunes. All she wants is to find the girl of her dreams, which is hard to do with the meddling of the sadistic Mariya and his sharp-tongued maid Matsurika Shinouji. Maria†Holic Alive continues the story of Kanako as she deals with being Mariya's roommate and aims to find true love, while enduring high school itself. [Written by MAL Rewrite]

An OVA summarizing all 25 episodes of season 1 from Lelouch's viewpoint.

In a world where humanoid armored weapons known as "Titatonostrider" ("TS" for short) are used in warfare, troops from various countries converge on the island of Oahu, Hawaii, including Ao Isami of the Japan Ground Self-Defense Force and Lewis Smith of the United States Marine Corps. Isami and Smith cross paths during battle, but suddenly, their teams are attacked by an unknown enemy, scattering soldiers and sending their forces into disarray. In order to save their friends and survive on the deadly battlefield, they must fight with every ounce of courage and pride that they can muster.