Sana (girl) was a student. Haruka's (the boy) father was her teacher and they fell in love, and she wanted to marry him (the dad). Boy witnessed them having protected sex. Two years pass. Sana graduated, is gonna marry the dad (I think?) Haruka decides he wants to make her his. Waits for the house to be empty, has rapes her without a condom
Really hot. Wondering if it will have sequel story, but considering this series are just one-shots with similar scenarios it's unlikely