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...
The appraising of jewels other than 
diamonds is known as valuating,
يُعرف تقييم المجوهرات 
،بخلاف الماس بالتّثمين
La valutazione dei gioielli diversi dai diamanti
è conosciuta come "stima",
A avaliação de outras pedras que não
sejam diamantes é chamada de identificação.