Hop Step Jump!

A 32-year-old unmarried man begins work as a janitor at an all-girls' high school, where he meets a girl he believes he will marry. One day, he hears a scream and finds her distressed over a frog trapped in her clothing. She has an allergy to frogs and soon faints. Neither a teacher nor her friend is willing to handle the pink frog due to fears of poison, leaving him to remove it. During the process, the frog bites his injured finger and drains his blood, causing him to faint. Upon waking, he discovers he has changed in some significant way.