- Kousuke Seto: When Seto entered Marry's home, she warned him not to look at her in the eyes. He misunderstood what she meant and thought she was just shy. As Marry started to cry and wouldn't stop, Seto placed his earphones in Marry's ears and made her listen to his music. She was delighted and he gave her his hood as a present. He was the one who later brought her into the Mekakushi Dan and he became her first friend.
- Momo Kisaragi: After initial problems of shyness and a little accident where she spilled tea over her head, Momo grew to become one of Marry's best friends.
- Shion Kozakura: Marry's mother who died saving her from humans. She wrote a diary about how much she loved Marry. She is 1/2 human and 1/2 Medusa.
- Azami: Marry's grandmother and Shion's mother. She is a full Medusa. Azami saved Marry's life after she and Shion entered the Heat Haze by giving her the Queen Snake, allowing her to have another chance at life and happiness.
- Tsukihiko: Marry's grandfather. She personally never met him.
- Shuuya Kano: When Kano teases Marry about getting a job so she could pay for Momo's phone in the manga, Marry gets angry and freezes Kano with her eye power. Kano also makes teasing jokes about Marry, like in the Children Record Booklet.
- Tsubomi Kido: She meets Kido at the end of Imagination Forest, and soon joins the Mekakushi Dan. In the Manga, Kido also talks her into meeting Momo.
- Konoha: When Konoha showed up at the hideout, Marry mades him tea and offered to be his friend, as well as take him to meet her other friends.
- Snake of Clearing Eyes: The Snake of Clearing Eyes was able to exist because of Marry's repeating wish to see all of her friends again. As Kuroha, the Snake taunted her and killed her friends in order to force her to use her powers and reset time.
- Ayano Tateyama: In an alternate route in the manga, Seto brings Marry home with him the day they meet, and a young Ayano welcomes her into the Mekakushi Dan.