The class president of Takashi's class. Sasada believes that Takashi can see spirits, and constantly asks him questions about it, to which he replies that he doesn't have such an ability. Much to Takashi's chagrin, she wants to come along with him when he's visiting spirits. She possibly may have a crush on him in the anime, as she blushed in episode 5 when Takashi asked why she wanted to come with him to an abandoned train station (he was going there to see why Reiko had a ticket for that place). Luckily, he was rescued by Tanuma, who distracted Sasada long enough for Takashi to escape on the bus.
The story in the manga differs slightly, as Sasada moves away after the encounter with Shigure, so she has far more spotlight in the anime.