Hoshi no Omoide: I was transferred to another world

My name is Kyo Satou and I'm a 16-year-old student. I have a little sister that was named Sakura Satou and 3 years younger than me. I lived with my grandfather in Kyoto while Sakura lives with my mother and father. When I was born, my mother was still young and gave me to her father. I was raised by my grandfather. He teaches me how to cook, how to make a fire and some basic things. Since a kid, I never saw my parents only my little sister which my mother and father send her while they're busy. I never liked my parents cause they abandoned me. I always hold a grudge against them. I kinda lonely in school and I only have 5 or 7 friends and I hate to socialize maybe because I always been an alone child.