The plot of this game sounds like a cheesy pick-up line -- the game’s protagonist must create star children with female students in order to fight monsters and save the world. Given that childbirth is a long process, they have sped up the process using a Matryoshka doll. Ignore the science and just enjoy the JRPG wackiness instead.
The game is technically a dungeon crawler, where players require extra help to defeat monsters....so they procreate using magical energy and softcore psychic pornography. From these rituals, cute RPG characters are born.
The agreement for ladies to meet, become friends, and serve the protagonist is a little strange, but it does allow players to speed up combat and unlock features.
You can buy Conception 2: Children of the Seven Stars for $29.99 on the PS Store.