Well that was disturbing. A creepy muscular grandmother feeling her granddaughter up? Check! A giant worm creature that the main character eventually straddles? Check! Random pointless ecchi? Check!
Honestly there isn't a point to reading this unless you want a bit of ecchi. The story is crap (a version of Little Red Riding Hood, essentially) and otherwise is a useless one shot.
It an alternative story to Little Red Riding Hood. I found it very interesting because it took the story and changed it completly. Its a one-shot manga so if you have a free time and you wanna read something. It wouldn't hurt to read this