Ichiko Ayase
She is the Vice President in the Student Council. Spoiler It is later revealed that she is the leader "Kuraki" of the Happiness Club that destroys the happiness of other people. She is the little sister of Kazuo who committed suicide after being dumped by Shiraishi. She started harassing other people because she thought that by taking their happiness, it will become hers. She later became devastated after learning the truth from Shiraishi that her brother was happy when he committed suicide and he was the one who stole the happiness from their family.