Help me identify a Japanese/Chinese coin

I'm kinda new to the hobby so I'm gonna need some help. My grandfather gave me a big box of coins, but he doesn't know the backstory to this coin. Any clues appreciated!  🤍

Diameter: 26 mm 

Weight: 5 grams

Welcome to Numista!

Looks to me like a Chinese cash of Sheng Tsu, aka K'ang Hsi, 1662-1722, Boo Yuwan (Board of Works) mint. 

https://www.calgarycoin.com/reference/china/china8.htm#kang%20hsi

Kangxi
https://en.numista.com/catalogue/index.php?r=kangxi&ct=coin

Seeker55

 

Looks to me like a Chinese cash of Sheng Tsu

Wow that's really cool! Thank you

Geison is also correct, with a more up-to-date name for the same emperor. 

Until around the 1970s, the romanization of Mandarin was done according to the Wade–Giles system. This emperor was therefore called K'ang-hsi, this is the system used for this outdated introduction to Chinese coins from calgarycoin.com. Since then the pinyin system has been internationally adopted. This is the system used on Numista. The emperor is called Kāngxī and the Numista records of the Qing emperors are well documented.