Little Witch Academia - Season 1 Episode 7

Akko studies hard for her exams, but still struggles to get decent grades despite Ursula's tutorage. After getting into a fight with Hannah and Barbara, Akko is threatened with expulsion from Luna Nova should she fail her final exam, which requires an understanding of fish language. While attempting to bribe the fish philosophy teacher, Pisces, Akko accidentally drops her down a drain into the school's sewage system. Transforming into a merman to search for her, Akko comes across a sad fish and chooses to use her emergency magic reserve to free its family and Professor Pisces from a poacher's trap. When Akko is once again faced with expulsion for her actions, Pisces gives her an A in her exam (the theme of which was "Altruism and Magic") for helping the fish family, while Ursula vouches that, despite the gap between her and her classmates, Akko's magic has improved considerably since her enrollment. After the fish Akko rescued are revealed to be an endangered species, her expulsion is cancelled and she is given a less severe punishment instead.