In the office where Natsume Iroha works, the meeting room walls have been replaced with one-way mirrors. It was supposedly an initiative to eliminate stuffiness and create a more open environment. While people outside can't see in, those inside can clearly see out—a strange, surreal setup. Amid this unreal atmosphere, Natsume gradually begins to feel her heartbeat quicken. One night, inside that meeting room, she gives in to the pent-up desires she had been suppressing. Because it was dark outside, she didn't realize the room was transparent from the inside.