An isekai, but one where the MC has been living in the other world for a while already. Al, a summoner, tries to summon some monster helpers for a quest but accidentally summons loli monster girls instead: a succubus, a lamia, a slime, and a zombie. They aren’t powerful enough to help, but (after the succubus does what succubi do) he finds out having s*x can boost their magic. However, each species of monster girl presents a unique challenge in getting that method to work.