Nafumi Shintani

Nafumi Shintani (新谷 ナフミ) is an image-conscious art teacher who drugs and tortures her male students. She serves as the main antagonist of the eleventh chapter of, "The Boy's Portrait".

Personality
Shintani is portrayed as well-respected among her students and as especially popular with the male students. She takes advantage of the students who are attracted to her by drugging them with tea and torturing them with cigarettes and palette knives. Her sadistic personality is hidden beneath a gentle façade. She is also shown to be apathetic to her victims; She is saddened by Yuuki's accidental death only because it prevented her from finishing a sketch of him.

The Boy's Portrait
A week prior to the story, Shintani accidentally kills her student, Yuuki Noda by pushing him against into a table in the art room. In order to finish the sketch she started with Yuuki, she recruits an unnamed boy to take his place as a model. She drugs the boy with tea and attempts to strip him naked but is interrupted by a young girl claiming to be the youkai Renoir who tortures humans by trapping them in paintings. In order to avoid being trapped by the youkai, Shintani has to avoid lying to her. The girl questions Shintani about the nature of Yuuki's death, implying that Shintani had been abusing him prior to his death. Shintani refuses to admit any wrongdoing and fights with Renoir, who is seemingly defeated and shatters. As Shintani gloats in her victory, the girl is revealed to have been a different youkai, Higanbana, who was masquerading as Renoir. The real Renoir is the boy who Shintani drugged. Renoir reveals himself and reveals the fact that Shintani had lied to him earlier when he asked about Yuuki's death. Shintani attempts to escape before Renoir can put her in a painting, however she becomes trapped when she gets to the stairwell. While she is on the stairs, Renoir forces Shintani into M.C. Escher's Ascending and Descending.

Trivia

 * Shintani smokes but hides this fact owing to the decreasing popularity and acceptableness of smoking.