Complex sentence: When Kan finds the bottle, he discovers that a sneeze summons Hakushon and that he must grant the wish of the person who sneezed, while a yawn summons Akubi and she must do the same for the person who yawned.
Split into simpler sentences: When Kan finds the bottle, he discovers that a sneeze summons Hakushon from the bottle and that he must grant the wish of the person who sneezed. Akubi must do the same for the person who yawned.