Most humans aren't allowed to have much to do with the haibane, so this is a short list.

They run the bakery Hikari works at.

He runs the cafe Kuu works at. He seems fond of Kuu, and helps out Rakka when she's feeling down.

He sells used clothes to the haibane. He enjoys having the haibane around, and thinks they bring blessings. He offers Rakka a place to get away if she needs it.

She works at Old Home to help raise and teach the kids. She's not afraid to give lessons to the older haibane if she thinks they need it, either.

Kana's boss, he runs the clock tower in town. He's quite nice, but Kana doesn't think so. He thinks she's got great potential and is trying to get her to do her best.
Oyakata isn't his name, but it's all Kana ever calls him. It means "boss" or "master".

Sumika is Nemu's mentor at the library, but has to take maternity leave. She and Nemu have been friends for a long time.

There are a lot of people in Glie, and it's only natural that some of them are haibane fangirls...