Yandere- They can be described as stalkers. These people can look cute and innocent but they can be highly dangerous. They would kill or attack everyone that will stand against or in between their love. These type of people are psycho and insane.
Yangire- At the beginning Yangire seem to be friendly, nice and cute, but later their personality changes and they become aggressive. It can be a result of mental illness. It's similar to Yandere but it isn't a result of love obsession.