Housekishou Richard-shi no Nazo Kantei S01E01 - Seigi of the Pink Sapphire

Second-year Kasaba University student Nakata Seigi rescues a foreigner being harassed by drunks. Wavy blond hair, blue eyes, and clear skin. The man who speaks unfaltering Japanese is Richard, a very competent jeweler with customers both domestic and international. Thanked by Richard for being a "hero of justice," Seigi hires Richard to valuate a memento from his late grandmother, a pink sapphire ring. Through Richard, the mystery hidden in the ring is eventually revealed...