My spirit animal is a F–Rank gecko - Chapter 12: Not so welcoming ceremony (1)

On his usual way to home Mikado Tsuchio fell into a hole that suddenly opened on the ground. Just like that, Tsuchio falls in a different world, he lands on a Grappler Wyvern and manages to tame it.

Tsuchio decides just like that to live in the other world, the reason for his quick decision: he wants to make a monster girl harem.

After accidentally falling, she actually finds herself bound to a Second Female Lead Counter Attacking System!

One day, when a novelist woke up from a restless sleep,he realized that he had transformed into his 12-year-old self.

Liu Duo was a young girl whose grandmother sold her to four brothers with the intent to be a bride. Unwilling, she ran away the following night, only to fall unconscious while trying to get away. Unexpectedly, however, she was reborn with the spirit of a 25 year old woman, also named Liu Duo.

- Description from Novelupdates