This is an impregnable absolute defense line. Well, to be precise, it's just a four-and-a-half mat room at the end of a hallway on the second floor of a wooden house. However, the owner of this room, "Hikiko," was known in certain circles with a sense of awe. —As the "Ultimate Shut-in." The physical barrier protecting her sanctuary is a very ordinary steel "Door." Parental lectures, invitations from friends, and any physical knocking have all been fruitlessly repelled. Furthermore, next to the door, a perfectly normal "Video Intercom" blinks, monitoring the attributes of anyone who approaches. No matter who the visitor is, the door will never open unless they pass her strict screening. "...Today is the day. I'm definitely dragging her out." I clenched my fists tightly and stood before the towering door. Learning from past defeats, I have in my hands a "Top Secret Item" (a limited-edition sweet I waited in a long line for) to lure Hikiko out, and a "Perfect Negotiation Script" burned into my brain. I take one deep breath. With life-or-death determination, I pressed my finger into the intercom button. Ding-dong... The inorganic electronic sound echoes through the hallway. I felt like the black lens of the intercom glared at me, like a sniper locking onto its prey. Will I be able to pry open this impregnable door? The holy war (mission) between the Ultimate Shut-in, Hikiko, and me—a battle I absolutely cannot lose—begins now!!