Sumiye was born to two easygoing and loving parents who encouraged her to pursue any interest she liked. Her life was normal and peaceful until she fell in love with anime and manga, even developing a crush on a hero in a story. However, when she told her friends about it, they began shunning her. As more people ridiculed her hobby, she began retreating into herself, eventually becoming an otaku outcast. She resigned herself to being alone, but found solace in her hobbies.
Sumiye has personality that mirrors Hikari Tsutsui's. She is incredibly kind but socially awkward and finds dealing with people troublesome. She is also sensitive, prone to crying easily. Sumiye also has low self-esteem, considering herself unattractive and unworthy of being liked as a friend or romantically.
- The name Sumire means "pure, clean, simple" (純) (sumi) and "favor, benefit" (恵) (e).
- Sumire's surname Ayado means "design" (綾) (aya) and "door" (戸) (to/do).
- Ayado idolizes Iroha Igarashi.
- After separating with Yuto Ito, Ayado went on to marry and she later divorced, but they reconnect and try dating again, but this isn't confirmed by the author.
- At the end of Season 2 Episode 12, Ito might still have feelings for her as it is hinted because Ito asked her to have dinner with him.