When Tomo Yamanobe's father—the former headmaster of Saint Mikhailov Academy—disappeared, he left nothing behind except for a piece of art called the icon. Soon after his disappearance, rumors of a serial killer attacking female students of the academy began to spread. As Tomo and her sister Mafuyu Oribe head home after being tormented at school, Tomo trips over an injured silver-haired boy who abruptly vanishes while being tended to. Mafuyu goes to look for him, only to discover that the church holding the icon is burning down. When she tries to save the painting, the rumored serial killer suddenly attacks her with a mysterious ability to control magnesium. Appearing out of nowhere, the silver-haired boy, who can control iron, rescues Mafuyu. Mafuyu finds out that the boy, named Alexander Nikolaevich Sasha Hell, is a qwaser—a being who is capable of controlling an element through the power of soma, received through the act of breastfeeding. Confused by the ordeal, Mafuyu attempts to move past it with little luck, as Sasha transfers to her class the next day. What will become of Tomo and Mafuyu's normal school life with the danger of other qwasers looming close to them?

Sasha is partnered with Hana as his new Maria. They infiltrate an all-girls academy, forcing Sasha to crossdress, in search of a Qwaser-related artifact called the Magdalena of Thunder which has appeared in one of the students. However, they have some competition in their search of it. (Source: ANN)

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 unique being known as a Sekirei, a humanoid extraterrestrial with extraordinary abilities. These aliens are known for kissing humans carrying the Ashikabi gene in order to awaken additional latent powers deep within. Recognizing the potential within the seemingly insignificant youth, Musubi kisses the bewildered Minato, 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.

Kusano's first errand - A ten minute OVA that came along with the 6th vol. limited edition of Sekirei. Kusano finally tires of nobody admitting her as Sahashi's potential wife, so she insists on joining Musubi and Tsukiumi on their shopping race to show her abilities. An iffy day ensues.