Saya's neighbor and the owner of Guimauve, a coffee shop near Saya's home. He is also a friend and junior of Tadayoshi back in their high school years, although he attended it much later than Tadayoshi. Fumito usually serves breakfast for Saya and makes bento lunches for her. He once stated to Saya that she is special to him, and that she is more important to him than anything else. After her battles, he expresses his concern towards Saya by bringing coffee and guimauve to her after her battles. Saya once questioned him about his guimauve asking if they were always pink in color—he is mysteriously states it depends what is mixed in them.
In the penultimate episode, it is revealed that he was the one behind the experiment to see whether Saya would revert back to her previous personality thus making him the series's main antagonist.
Nanahara fell in love with Saya a long time ago. Worrying that the decreasing number of furukimono will result in food shortages for Saya, he started experimenting with turning humans into furukimono. The only furukimono he created that lived a decent ilfespan was Mana Hiiragi's father, who was killed by Saya. Given that he couldn't create food, he instead got Saya to kill the contract, limiting the number of humans furukimono could eat in the hopes that their population would grow. He also fed Saya human meat and blood tasting food during the experiment in the TV series to help get her to start eating humans. At the end, he took Saya's blade and killed himself to get Saya accustomed to killing humans. It was revealed that Saya's inability to eat humans is psychological.
