Sumire Karino (Tadashi's mother) is the director of Hakusenkan and is a very fierce and strict woman. She lets Tadashi do whatever he wants during school as long as he stays in the top 5. She also has a hobby of throwing darts to see what punishment S.A. gets, and is often shown throwing them at a dartboard in her office, with incredible accuracy.
She is also a past student of Hakusenkan, along with her husband, and they were also very popular during their school days.
At first she is seen as a strong, fierce and strict woman. She was also seen as a woman of her word sending Tadashi to Bungee Jump when he did not make it to the Top 5. However, she is seen to be a loving mother that supports her "wandering child". Despite submitting to the pressures of Aoi, she does so reluctantly and was very happy to get the Special A class re-admitted.