Shino is Kotarou's cousin, a small child with a free spirit. She gets upset very quickly and easily and hates being left alone. Like Kotarou, she can see angels, demons, and ghosts. It's important to note that she is different from her grandmother, also named Shino, who appears in the manga.
In the manga, Shino plays a significant role. When she first appears, she is lost in an amusement park where Shia and Misha find her. Shino immediately takes a liking to Misha but dislikes Shia because she gets headaches around her, similar to how Kotarou used to react. In the manga, Shino is 1/8th demon, like Kotarou, and shares a lineage with Shia, who is her great-grandmother. Her grandmother, also named Shino, is portrayed as strong-willed, much like Uematsu in the present. After Shino's father is hospitalized (her mother is deceased, like Kotarou's), she moves in with Kotarou. Although her appearances decrease as the series progresses, she remains part of the cast and appears in the final chapter.
In the anime, Shino has minimal screen time and does not appear in the introduction. She only features prominently in one episode where she visits a theme park and runs away after learning her father is in the hospital. Misha and Kotarou eventually find her, and Misha takes her to her father.
(Source: Wikipedia)
