I will give you a like just for your endurance and perseverance, if you are 20 hours in and you haven't finished the one room class part... well on the bright side you have countless hours ahead of you to keep practicing your Japanese so がんばれ! (it gets easier with time, you won't notice at first but it does)
That artist likes yanderes but companies are mostly avoiding yandere characters right now... the closest it gets is the hidden heroine, Tomiko (who has no profile on the websites but actually has a fairly hilarious path of roughly equivalent length to the others)