nagatoro_hayase
Previously-original character created by 774 (nanashi), now serialized into the manga Ijiranaide Nagatoro-san.
She's described as being S-dere (Sデレ), or Sadodere, a term for a character who gains pleasure by toying with and teasing their love interest. Frequently torments her senpai/boyfriend, Hachiouji Naoto. The game 774 made of her lists her under the name "Nagatoro Hayashi". She has a sister named Misaki and a brother named Taiga.