An Angel Sometimes Wants to Drink Apple Juice (2015)

Mark, a cupid angel whose human memories are all erased, goes through a training of making people fall in love with his instructor, Matt. Being informed of apple juice, a sinful condemnation that makes the drinker forget things, Mark faces an existential crisis between obeying God's order and following his heart when he encounters his ex-girlfriend, Kate, with her current boyfriend.