Shizuku Hirasawa (平沢雫 Hirasawa Shizuku?) is a previously anonymous under-classmate of Tomoko whom Tomoko helped when she became sick during her high school entrance examination.
Shizuku is a nervous girl who becomes overcome by the stress of the high school entrance exam. On duty, Tomoko takes care of her. She is so nervous because she promised to attend the same school as her boyfriend. However, when she passes the exam and he fails, she cheerfully declares that no matter how far apart their hearts are, they remain connected. Tomoko deems this the behavior of a "scum." Nevertheless, as of Chapter 142, she continues to date him though she cheerfully observes that, "failing seems to be the only thing he's good at."
The following year she eagerly greets Tomoko as her "senpai," or "upperclasswoman." Tomoko accepts her as her kōhai but for entirely Tomokoesque reasons. She then earns the wrath of Emiri Uchi. When she notices Tomoki, she earns the wrath of Kotomi.
(Source: watamote.fandom)