Leina eats a toadstool that really doesn't agree with her, and has an absolutely hilarious scene where she throws up. Then she apparently starts hallucinating.
examples from "Hide & Seek"
Chapter 22 features the long awaited showdown between Elina and Leina but, before the match can begin, Elina's pent up feelings causes her to lose control and literally cat pounce her sister, giving all of Gainos a free show! Hilarity Ensues, especially their father's reaction when he sees the debacle!