Shijima Tsukishima (月島しじま, Tsukishima Shijima, also known as Shimeji) is the protagonist of Shimeji Simulation. She's a first-year high school student. She has spent 2 years of the middle school living entirely in her closet because of things that made her hate it (ss01). She's an apathetic person, not caring much about what's going on. She always denies her relationship with Majime.
Shimeji is a slender girl with long black hair (long and silky, as said in ss14 by Majime's mother). She has blue eyes (although many people think they are black, because they are drawn black in the black-and-white manga) and two shimeji mushrooms sprouting from her head.
She is often seen wearing her school uniform or the gym uniform (during the club activities), although she is also known to have the gray dress and the pyjama.
Her older sister doesn't particularly care about Shimeji. She's friends with Majime. She has also influenced the Mosasa Dogs' namess16.