Zero no Tsukaima

Synopsis

Louise continues her lovey-dovey behavior towards Saito, which freaks him out, as well as caused a misunderstanding with Siesta. In desperation, Saito demands that Montmorency create an antidote, but she refuses to help, until he blackmails her into helping (Saito learned from Siesta that potions which change a person's emotions are illegal). As the antidote requires "the tear of a water elemental", Montmorency and Guiche lead Saito and the love-struck Louise to Lagdorian Lake where they make contact with the Water Spirit. She is flooding the land so that she can search for her stolen precious treasure but she is being hindered by magic users. Saito volunteers to deal with them and he and Guiche fight the intruders who turn out to be Kirche and Tabitha. Saito promises to find whatever the Water Spirit has lost. The spirit trusts his word as "Gandálfr", and gives him the antidote.

(Source: Wikipedia)