Yukino Houjou

She is the oldest Gate Keeper in Japan, having been born in 1169. However, she has stopped aging and appears in 1969 as a young girl in a white kimono.

Ruriko and Shun first met her during their mission to recover a crashed plane and its cargo at Mt. Daisetsu in GK. Like her name Yukino suggests, she commands the Gate of Ice and Snow, being able to summon blizzards and hail. Yukino is also capable of teleportation and sending off visions that let a person to see a scene without actually being there. She is dubbed as the most powerful Gate Keepers in the series by Reiji Kageyama. One of her unique traits is the fact that she converses in Tanka poetry. Though she does help the A.E.G.I.S. members, she is not an official member of A.E.G.I.S. She also has a pet ermine, Hisame. She is closest to Shun's sister, Saemi Ukiya.

Yukino re-appeared in GK21, taken up residence in Tategami High and have been the source for the rumours of ghosts that come out at night. Tragically while her body has not aged, her powers and strength are finally waning and long ago gave up appearing in front of her old friend, Saemi. Recognizing a similar sadness in the daughter of an old friend, she helps and befriends Ayane and Miu.