[Tutor] Extreme Sun

Sasakawa Ryohei has known since he was a child that he must do his best to protect his only sister Sasakawa Kyoko. When he was twenty-five years old, Sasakawa Ryohei really protected Sasakawa Kyoko at the cost of his life. But... "Why did I go back to 20 years ago when I opened my eyes? This is extremely unscientific!" The above facts prove that there is still the word science in Sasakawa Ryohei's brain. All in all, the eldest brother returned from twenty years ago when he was five years old, only to find that his sister was only three years old, so he made up his mind to protect Jingzi even more. In the end... Who knows?