This entry contains 2 characters since they are pretty similar in history.
KETSU AND MISTER SHI(SHISU?)/JIE SHI AND SI SHI
Japanese/Chinese: 竭氏, 肆氏
Japanese Pronunciation: Ketsu, Shisu(?)
Chinese Pronunciation: Jie Shi, Si Shi
The Jie(竭) and Si(肆) are clan names of the characters and Shi(氏) here works similarly to our “Mister” today. For more information, refer here.
2.Activities in History
Considering we only know the clan name of Jie Shi and Si Shi, but not their actual name. The Jie Shi and Si Shi in the manga might not be the same one we have in the history records. Anyway, i will post the one and only line I can find have about them in “ShiJi: Annals of Qin Shi Huang”
9th year(of Ying Zheng’s rule)……more than 20 officers including Guard officer Jie, Law minister Si, Bow officer Jie and Minister Qi were beheaded.
Pardon my translation above for the titles and position in courts as i cant really translate those well. Anyway this happened in the 9th year of Ying Zheng’s rule, the time of Lao Ai’s rebellion. These minsters and officers were accomplice to Lao Ai and Lu Bu Wei and were beheaded for their crimes.
Assuming Law minister Si is indeed Si Shi(Mister Si) in Kingdom, we might see Si Shi betray Zheng and join Lao Ai/Lu Bu Wei’s faction in the future and get beheaded. However, Jie Shi was killed in the first arc so the Guard officer Jie and Bow officer Jie might be other characters that were related to Jie Shi.