Umino Tsubame is one of the birdmen. Unlike the other four protagonists, Tsubame goes to a different school in Yokohama.
Tsubame's hair is short and light-colored. She has 162cm height.
As a seraph, her markings are blue in color.
As children, she went to the same cram school as Sagisawa. After Sagisawa started studying under a private tutor, they stopped seeing each other, although they met again a couple of years later.
Linker (繋ぐ者（リンカー）, Rinkā): Umino awakens her ability as a Linker when visiting her father's hospital and hearing his voice as he is dying.
- Tsubame is written with the kanji for "swallow".
- Her blackout motif is a plushie.