You get a show that treats tiny robot girls like actual characters instead of fanservice props, then strips that respect away the moment combat starts. The tonal whiplash between domestic slice-of-life and brutal mechanical warfare is the entire point, these aren't just cute companions, they're soldiers that bleed oil and get repaired on your kitchen table. It's cynical enough to work, sincere enough to matter.

In an ordinary future where robots are part of daily life, tiny partners called Shinki stand just fifteen centimeters tall and are built to help humans. They have intelligence and emotions, and they devote themselves to serving their Masters. Shinki can also be fitted with weapons and armor to battle one another, and armed ones are known as Busou Shinki. High school freshman Masato, newly back in Japan after living abroad, is served by three of them: Ann, an Arnval model, Aines, an Altines model, and Lene, an Altlene model. On his first day of school, they eagerly set about unpacking and tidying his belongings for their Master. Things change when a new Shinki, the belligerent Strarf, joins them. The series mixes slice-of-life comedy with mecha action and science fiction.