Asami is a friend of Sana and is in her second year. Sana met her when he got ditched by Nanaka when they were supposed to go to the student council meeting.
Episode 11 Spoiler:
In episode 11 it is revealed by Asami that she is the one responsible for the anonymous letter about Shuri and Shuusuke in the love hotel. Asami reveals to Sana that she had confessed her feelings to Shuri back when they were first-years but Shuri turned her down, and told Asami she would like to stay friends. Asami began to hate Shuri, but at the same time she wanted to remain as her friend, even if only for show.
Because Asami was used to hiding her feelings, she began to feel like her and Shuri really were good friends, but her attitude changed when she saw Shuri crying to her brother Shuusuke on the Ferris wheel at the carnival. This had been the first time Asami had seen Shuri like that, and Asami became bitter because she realized Shuri would only reveal her feelings to Shuusuke and never to her. Asami thinking about how she had carelessly confessed her feelings to Shuri and gotten hurt by it, decided that she wanted something bad to happen to the siblings and wrote the letter on the day she knew they would be visiting their mothers grave. Asami is also the one who drew the love umbrella on the chalkboard, and she stated that she didn’t have any regrets when she saw Shuri crying, instead she got a rush from comforting Shuri on the bus to the old folks home and wanted to cause Shuri more pain so that she would show her the face she would only show Shuusuke.
Even though Asami wanted to see Shuri suffer, she ran and sacrificed herself to save Shuri when she saw her in danger from Kajii, and she doesn’t understand why she did this. Sana explains that it’s because she wanted to save someone dear to her, and that these were her true feelings. After hearing this Asami breaks into tears. (information taken from Random Curiosity)
