Mushoku Tensei: This Time, I'll Show My True Strength to Protect My Family

[Sylphie as the sole heroine | Pure romance, no harem | Original male protagonist] In my previous life, I couldn’t protect a single member of my family. The night I was hit by a truck, I locked eyes with a strange, chubby man. When I opened my eyes again, I had become the eldest son of the Greyrat family, named Pollux. A younger brother with light brown hair lay beside me, staring at me. In this life, I was born with green hair and absurd strength. My magic couldn’t compare to my little brother’s, but a sword felt right in my hands from the moment I picked one up. When I was four, I came across a little girl in the village being pelted with mud. She had green hair like me, and her name was Sylphie. Later, she learned the sword by my side. Later, her hair turned white. Later, she waited for me for many years. And later still, someone claiming to be a "god" laughed in my dream. This time, I won’t just stand by and watch.