Before we get to any adavance things, lets start with basics.

Yandere (ヤンデレ) is a portmanteau of two Japanese words yanderu (病んでる), meaning to be sick, and deredere (デレデレ), which isdefined as strongly and deeply exhausted, infatuated, moonstruck, head over heels, or lovestruck, but in this case used for "lovestruck."

Yanderes should not be messed with, that means Don't play hard to get, Don't make him/her jealous, and most importanly, NEVER i repeat NEVER make him/her angry.

There are two main kinds of Yandere, Possesive and Obessive.

Possesive yanderes will kill you JUST to keep you to themselves, so yeah be careful.

Obessive yanderes will get rid anybody who standes between your "relationship"