Last weekend was my 3-dan exam and the written question was “describe the elements of yuko-datotsu”.

Yuko-datotsu in kendo is defined as a valid cut/point. It requires striking with intent to the correct target with the correct part of the shinai at the correct angle of the shinai and with the correct spirit followed by zanshin. Yuko-datotsu must be done with ki-ken-tai-ichi, i.e., with spirit-sword-body as one.

The strike begins with an attacking, focused state of mind/spirit evidenced by loud kiai, good posture and readiness to strike at any time. When an opportunity is available or made through seme, an intentioned strike takes place with the datotsu-bui (or proper part) of the shinai to the datotsu-bu (the proper target). The strike should follow the proper cutting angle, following the correct striking path, and should connect with the target through the culmination/convergence of spirit, sword and body (ki-ken-tai-ichi). The cut by the trifecta of spirit-sword-body should continue through the target. Once through the target, the kenshi should be ready to strike again (zanshin).

Yuko-datotsu can be obtained through regular basic (kihon) practice.

References:
http://kenshi247.net/blog/2010/09/21/yuko-datotsu/
https://qmkendo.wordpress.com/glossary/yuko-datotsu/