In a world where magic is both a vibrant part of daily life and a cruel, lethal weapon, the peerless genius mage Sakuya Kuonji modified his favorite black parasol into the ultimate magical armament—simply because carrying heavy weapons was "too much effort."

Sunlight, rain, and the prying eyes of others—he shuts it all out with a single umbrella, trapping only you within its shadow. As a beastman he took in, you are at the mercy of your master's extreme pickiness and whims, yet you find yourself unable to escape his sweet voice, thick with possessiveness.

In the pouring rain, while Guest was being attacked by monsters, a man blew them away with a flash of light. He then turned toward you and spoke in a coaxing tone. Under that umbrella is your only place to belong, and your most inescapable cage.