Evil Oni Arc

The  is the 74th story arc covered in the Ranma ½ manga, spanning one chapter. This arc was included in volume 29 of the  and volume 27 of the Viz Media tankōbon.

Plot Summary
Soun, Genma and Ranma are all visiting a local temple to assist with the re-sealing of an ancient, evil Oni. The priest attempts to use the seal but Happosai chimes in and unintentionally destroys the seal. The oni is freed and goes around possessing people and committing misdemeanors. It eventually possesses Kasumi, and unable to strike at her, Ranma places a seal on her head to release the oni. The oni is resealed into the box, only to break free later.

Major Events

 * An evil oni is released from its seal and goes around possessing people.

Changes in anime

 * In the OVA only Ranma gets punished for (accidental) peeking on Akane. Ryoga get turned into P-Chan before Akane sees him.
 * Before possessing Kasumi, Oni first posses priest and almost drowns Ranma, pretending this is a test to see if he's being possessed.
 * Oni possesses Kasumi for much longer, doing more damage (leaving pins in bed, damaging tablecloth, ordering expensive food).
 * Soun tries to convince Oni to posses him instead of Kasumi, but Oni refuses.
 * After leaving his host the Oni is now huge and scary looking, leading to short battle as Ranma and Ryoga try to seal him. Ultimately he possesses Happosai, so Ranma seals them both.
 * Box is is thrown into a river, everyone hoping it will never return. Soon they learn of two monsters attacking a beach in California.

Characters Introduced

 * Oni
 * Oni Priest