Seori♀

Seori is a hashihime (bridge princess) that has been around for a very long time. She claims to have lost track of how long exactly, which leads to her to say "somewhere between 2000 and 3000 years" when talking about her age. Keiji at first refers to her as a homeless person, seeing that she lives in a tent under the bridge that is her haunt.

Often seen as the older sister of the group, Seori's primary focus seems to be her distaste for affection and love between couples. Despite her purpose as a hashihime, she's actually good-humored and has a tendency to be playful. Her interest in Keiji stems from the fact that he is a human that can see her and talk to her on a normal level. The fact that she is lonely and bored is also something that helps her sympathize with Keiji.

[From Moroboshi Yuumei's review]