Sanae is a young girl with short black hair, grey-colored eyes, and a light complextion. Most notably, she keeps a very stoic facial expression, regardless of her mood. In school, she is seen wearing her standard uniform. Outside of school, she is seen wearing more casual clothing.
Sanae is a very blunt, yet caring and intelligent girl. Known for always having a very stoic expression and demeanor, Sanae likes to keep to herself. She is extremely athletic and is particularly adept at running and swimming. Underneath her typically expressionless exterior, Sanae is shown to care greatly for her two closest friends, Mina and Yukari. The three girls are constantly seen together, both in and out of school. Sanae may have a soft spot for animals. In one instance, Sanae was chasing a cat that had taken Yukari's snack. However, upon realizing that the cat had taken the snack in order to feed its kittens, Sanae decided to let the feline keep the stolen snack.
- She can drink dark coffee with ease, much to the surprise of her friends.
- She only smiled once in the anime, in Episode 6 of Season 3, after Takagi hugs Nishikata by the end of the play.
- In the Season 3 opening, she is seen tailing Takagi and Nishikata with Yukari and Mina.
- She has a sister who works as a teacher at the same school she went in and is engaged with Tanabe-sensei.
- Originally, it was hinted in Chapter 108 that Takao's crush is Sanae, but it is later confirmed in Chapter 112 after Takao blushes when realizing Sanae had arrived during his beach trip. It is unknown whether or not Sanae shares a similar interest.
- Sanae's age in the spin-off is never revealed, but estimated to be around 26 - 27 year old.
- Her age being around 26 - 27 year old is due to the fact that she went to the same school and class with Takagi/Nishikata. In Chapter 31, Takagi mentioned "it has been over 10 years since those days in middle school" while reading through her middle school graduation album. Since the age students graduate from middle school in Japan is 14 - 15 year old, then add over 10 years to it. 14 to 15 plus more than 10 is around 24-25, and raised to 26 due to the "more than" part of her comment.
|Main||Takagi • Nishikata|
|Supporting||Mano • Nakai • Sanae • Yukari • Mina • Takao • Kimura • Hamaguchi • Houjou • Tanabe-sensei|
|Minor||Sumire Takagawa • Tunnel Fisherman • Tunnel Fishergirl • Tunnel Misc • Principal • Mano's Friend • Class 4-2 Unnamed Girl|