High School Life (Marriage Hunting) in a World Where the Male-female Ratio is 1:15 and C*astity is Reversed

The main character has memories of a previous life in Japan. Reincarnated in a c*astity-reversal world similar to Japan, the story is about trying hard in high school life (marriage hunting). The school the main character goes to may not have much of a c*astity reversal element. The ratio of male and female students is similar. Outside of the school, it is not limited to that.