Higurashi no Naku Koro ni Rei

Synopsis

During a picnic with Keiichi, Rena accidentally swallows one of the mysterious "Fuwazaru Magatama" which falls from the sky, and begins acting lovesick. Rika explains that the seal on the magatama has been broken, and that whoever possesses the red magatama will fall blindly in love with anyone holding its white counterpart. Everyone reasons that Rena must have swallowed the red magatama and sets out to stop her and find the white magatama. It winds up in the possession of Tomitake, then Takano, and finally Oishi, each of whom gradually come to accept her love under the magatama's curse. Keiichi manages to obtain the magatama after beating Rena and Oishi with Akasaka in a game of mahjong. Oishi fumbles it and Keiichi ends up accidentally swallowing it as well. Rika lifts the curse before Keiichi can fall under its power, and Rena returns to normal. Rena, who is grateful to Keiichi for helping her, expresses her feelings toward him, though she isn't sure if it's part of the magatama's power. Tomitake and Takano still appear to be infatuated with Rena and fight over who gets to keep her.

(Source: Wikipedia)