Koharu's younger twin sister.

Among her siblings she's the most timid. Quick to get flustered. She's always worried about something.

Even when there's nothing there she trips and falls.

When she was younger, anytime there was a problem her older brother helped her so she is rather pampered.

She relies on her older brother so much that she believes that what he says is completely true to the point that when he tells total lies she totally believes him.

This timid Hiyori has no experience in sex, but is rather curious about it.