 When Shūrei calls doctors to treat the disease in Sa province, Rin designs a smooth knife suited to surgical operations; Rin later designs a centrifuge-like device to separate out sand from adulterated salt.She fell in love with Yūshun Tei when he was still Ensei's assistant and repeatedly proposed to Yūshun on the Autumn Festival (an event similar to Valentine's Day, when girls give handmade gifts to someone they like).For years, Yūshun had always rejected her.