Kyoudai☆Henshin Nau

Suddenly, a strange plant appeared in the corner of the garden. That was the beginning of the incident.
The protagonist intended to throw it away, but his sister used it as an ingredient in miso soup, and when he ate it, strange things began to happen.
His consciousness was transferred to the family dog, then his sister, and he transformed into a cute girl.
At first, the protagonist panicked, but he decided to accept it, realizing that panicking wouldn't change anything.
He decided to take advantage of his position and have some fun, and enjoy himself to the fullest.