Sapphire is a young woman with blonde hair, blue eyes, and shares a passing resemblance to one of her ancestors, Lillian Weinberg. According to Kohaku, she and her sisters are the prettiest women in the village.
Sapphire seems to spend a lot of her time, like her sisters, thinking about boys. She appears to be very honest about that fact, having no problems telling Suika what she wants in a man. In which case, out of the three sisters, she wants a boyfriend or husband who's handsome.
She is first seen along with her two sisters discussing their current needs with Suika, who plans on gathering information for Senku in order to bribe the villagers.
After Kinro is given glasses, Sapphire comments that she likes them.
When Senku makes electricity, she celebrates the age of energy.
When Senku asks Gen about Homura from Tsukasa's army, Ginro thinks he is stating what his type of woman is, with Sapphire, Shovel, Ruby, and Garnet seeming interested in hearing. However, Senku reveals Homura is spying on them.
She is later seen when Senku plays the record his father left, being amazed to hear the village founder.
- Her name contains the kanji for Blue (青 Sei) and Jewel (玉 Gyoku) and put together mean Sapphire (Seigyoku), in keeping with the fact that all other members of Ishigami village have names referencing metals and crystals.
|Male||Chrome • Ginro • Jasper • Kaseki • Kokuyo • Kinro • Magma • Mantle • Soyuz • Tetsuken • Ibara • Mozu • Oarashi • Matsukaze|
|Female||Garnet • Kohaku • Ruby • Ruri • Sapphire • Suika • Shirogane • Shovel • Turquoise • Amaryllis • Kirisame|