On a nighttime stroll, insomniac Ko meets Nazuna, a mysterious woman who is eager to show him what the night has to offer. Following Nazuna to her home, he discovers a surprising truth about her identity.
How can you fall in love with a vampire when you can't even track them down!? Nazuma remains frustratingly elusive, but Ko may have a nostalgic solution to this new problem.
Ko confronts Nazuna about their kiss. Later, running into Akira, he offers to take her to Nazuna's apartment. Overnight, the trio become closer in their friendship.
Ko meets Kiyosumi Shirakawa, a client of Nazuna's who resents her job, and realizes he is a younger version of her. Afterwards, he and Nazuna go to a nighttime pool.
Akira and Ko both have encounters with Mahiru, a popular student who claims to be their friend. Ko is given an ultimatum: fall in love with Nazuna within a year, or face certain death.
Seri-san speaks to Ko-kun about having issues with a guy. Ko-kun is horrified to learn that her intentions of dealing with her problem is through murder.
