Ch. 1. - 4: involves dolls/humanoids (for sex).
Ch. 5: 2 students - friends discussing a lovecrush -> go on a date together.
Ch 6: 2 students - "Bullied" and "Bully".
Ch. 7: Sensei x student who has lots of wet dreams during the day and with true friends who help him concantrate during the exam test.
Love-doll House Mamiya