This papercraft is Marisa Kirisame's Mini-Hakkero, a magical furnace in the game / manga series Touhou Project, the paper model is created by [unknown]. As revealed in Curiosities of Lotus Asia, it was originally given to Marisa by Rinnosuke Morichika after she stopped living with her parents.
The mini-Hakkero takes the shape of an octagonal block, made of wood, with the eight trigrams printed in a circle on its front. The internal components were originally made of iron or steel, but replaced by the mythical hihi'irokane metal after it became rusted. Despite its small size, it is a potent source of heat and magical energy; Rinnosuke describes it as capable of reducing a mountain to ashes. Marisa relies on it heavily for research and combat, most notably to power her Master Spark.
In addition to its normal functions, one of the furnace's corners releases a cool breeze, and the hihi'irokane model gleans negative ions from the air. Rinnosuke also believes that the mini-Hakkero may function as an amulet for protection and good fortune.
During the events of Double Dealing Character the mini-Hakkero was one of the weapons "corrupted" by the power of the Miracle Mallet. [Source: touhouwiki]
You can download this papercraft template here: Touhou Project - Marisa Kirisame's Mini-Hakkero Free Papercraft Download [Box] [Gavitex]