ZAI Style, Sonkyo Version.
Sonkyo is also the attitude of Japanese national sports such as sumo and kendo.
There is also a style that puts the buttocks on the heels.
The style of sitting upright has been the traditional Japanese lifestyle of sitting on tatami mats since ancient times.
Reallusion iClone7 Motion https://marketplace.reallusion.com/iclone/motion/search/kogene