Voiced by: Taneda Risa (Child) & Endou Aya (Adult)
Saki is the main character who has short brown hair initially and argues a lot with Satoru in the past.
2 years later, her hair grows to shoulder-length and she becomes Maria's girlfriend. Despite that, her feelings for Shun remain strong. She is eager to know the true secrets of the town after her encounters with several incidents. Tomiko also reveals that she has a strong mental stability capable of overcoming setbacks.
After a second timeskip, she now works at the Department of Exospecies Control, investigating and regulating the Monster Rat (バケネズミ Bakenezumi?) colonies.