At the same time every day, Kanta (Ino Kei) is able to mix with Natsume's (Ihara Rikka) world and spend a few minutes with her. He calls this phenomenon "mixing". Meanwhile, there are only three days until Natsume meets Yamatchi at a hotel. Who will it be? Meanwhile, Natsume, who lives in a world without Kanta, behaves bravely, as if she doesn't need the concern of those around her. However, when she is cleaning up Kanta's desk, she finds a bunch of notes addressed to Kanta from Natsume... Unable to contain her memories, Natsume stops by a game bar on her way home from work and gets drunk. That night, Kanta, who has mixed with Natsume's world, is surprised to see Natsume sleeping drunk in a messy room. Moreover, he finds men's underwear and a note saying, "I'll put the key in the mailbox" in the laundry..