I read till chapter 15.5 and I think this is not a yuri bait.
Spoiler!
The black haired girl is in love with the mc. Altough mc is trying to be with Ibara, she's starting to like the black haired girl too. There is a lot of kissing between the two girls and the black haired girl confess her feelings to mc.
The story has some twisted plot and I don't know what the f*ck is wrong with weirdo Ibara but It's interesting to read.
I believe in mommy supremacy