"My Stepsister Can't Be This Unrelated!"You know the whole "I have a new big brother when my mom/dad got remarried" is a stupid in anime its 10x stupid in live action. You aren't related by blood, its not incest, get over it.
And yes I understand that often times they do the "not really bro/sis or related" to get past censorship, but still that should happen when the characters are very young so they still grow up together. The trailer makes them look like their parents got married when they were in their teens. The guy might as well date a random girl from school who likes to roleplay as a sibling cause thats basically what this is.