Inside the Tentacle Cave manga volume 5 features story by Umetane and art by Abi.

With her kingdom lying in ruins, Queen Letitia is now the only defense left for her daughters against the cowardly Slimes. But her desperate last-ditch attempt at exterminating these (usually powerless) pests is for naught when the Slimes evolve into a creature far stronger than the most formidable mage! Will help ever arrive for the citizens of Fontilles? Or will they be trapped forever in this living nightmare?!