In Rune Factory 5, you can make a love potion by giving the correct items to the correct person. To make a love potion, you need to give a Hops Flower to Dylas. Dylas will then give you a recipe for the love potion. The love potion can be used on any character in the game, including the main character.
The love potion will cause the character to fall in love with the person who drinks it. If the character already has a lover, they will become jealous of the person who drinks the love potion. The love potion will wear off after a certain amount of time, but it can be renewed by giving another Hops Flower to Dylas.