Tenshi ni Narumon! EP9 - No Doesn't Always Mean No

Granny doesn't want Noelle to marry an "impure human" so she goes off in a huff when the family starts discussing marriage plans (ignoring Yuusuke's objections). Miruru and Granny team up to try to get Yuusuke out of the picture (Miruru telling Granny that she loves Yuusuke and wants him for herself). So the newest robot has a ukulele that can turn people into frogs. Slowly each family member is turned into a cute little frog until Yuusuke is the only one left (Miruru betrayed Granny so even she is a frog) and has to figure out how to save everyone. He thinks you have to look into the ukulele's eyes but it is the strings that hold the magic.