Don't know why this disturbed me

If you don't know I actually enjoying watching anime. Anyway I was watching Kannazuki NoMikeo (Destiny of Shrine Maiden). Well its about a girl named Himeko, who is the solar priestess and Chikane, who is the lunar priestess. Well We find out that Himeko likes Ogami because of their trials that each one had and leaned on each other. Well Ogami also likes Himeko and a twist is Chikane loves Himeko. Well anyway the story goes and we see that Chikane loves Himeko and wants to be with her but society won't let them and another person says that they will only be together in dreams. We also see in one scene that Himeko become unconcious and Chikane come to her aid but kisses her and rubs a breast. Anyway in one scene Chikane talks to Himeko and asks if she loves her and she says she does and then pretty much steals a kiss from her. The girl runs and asks what's going on and Chikane says she wants her and proceeds to rape Himeko. This was the part that got me. I have seen anime in various different forms but nothing to the point of rape. So as expected Himeko is distraught and wants to know why Chikane did this and the rest of the series trying to find out why she did that. Okay so fast forward to where the two meet again. Himeko asks Chikane why she did this and Chikane said he turned evil against her, because she wanted to destroy the world so they could be together. Chikane also said she loved her voiced and lips. Anyway Himeko didn't want to fight but Chikane made her and finally Himeko struck Chikane with her sword. So she wanted to know why and CHikane stalled but finally gave in. We find out that the priestesses lived former lives and when Chikane and Himeko vanished the evil one of them had to be sacrificed to seal the evil. Well Chikane had to kill Himeko and felt guilty over doing so. So she secretly turned evil so when Himeko had to kill her she would not feel guilty like Chikane did. So as Chikane is dying the both express their love for each other and comes to find out that they will be reborn. SO each time they will meet fall in love and then one will kill the other. But I said so much but the rape part is what got me. But if you9 want to know overall the series is a very good and everybody should rent or own the movie