Hatsune Miku from the Sekai of the Closed Window. She has slightly shorter twin-tails adorned with several large X-shaped hair ornaments. Her clothes are scattered with X marks. While she retains elements of Hatsune Miku, her overall color scheme is black. Her outfit is slightly oversized, as if she is withdrawing into her own shell. She tried to deliver songs to people in various places who harbored pessimistic feelings, but she struggled to reach them. During that time, she met Ichika Hoshino in a certain corner of a CD shop. "Miku!?" At first, she left immediately, but after Ichika performed a street live, she returned to her side. "I want you to teach me. How to sing." Afterward, through Saki and Tsukasa, Batsu Miku's presence spread to the students of Miyamasuzaka and Kamiyama, reaching those who deliver music. Because she was able to enter a certain Sekai, she began visiting everyone's Sekais. (Regarding why she could travel between Sekais, MEIKO from the Empty Sekai speculates that because Batsu Miku came from a Sekai formed by the overlapping fragments of multiple people's feelings, she shared commonalities with the owners of other Sekais.) Having gained confidence, Batsu Miku sent her songs to the people she wanted to reach, but... "Shut up!" They threw their smartphones away. Everyone she tried to reach rejected her, and finally, they all shouted, "Disappear!" In a certain Sekai, Batsu Miku wept in secret. Those tears became fragments of feelings and rained down upon everyone's worlds. Ichika, Minori, Kohane, Tsukasa, Kanade, and the others who touched them visited the Sekai where Batsu Miku was, but... Suddenly, the ground shook. When small feelings pile up and overflow, this Sekai... In that moment, Batsu Miku created something. "Thank you... and," "Goodbye!" Before everyone could be swallowed up, Batsu Miku let them escape. And then— The Sekai was enveloped in darkness. First person: I (polite/feminine)