こころよkokoroyoi
1.

A state of being that allows one to perceive external stimuli or their circumstances as favorable and enjoyable, creating a sense of comfort or joy.

2.

An experience characterized by a soothing or enjoyable sensation, often related to physical comfort, such as feeling refreshed by a breeze or experiencing restful sleep.

3.

Lacking any sense of unpleasantness or negativity; willingly accepting or engaging in something with a positive attitude and without reluctance.

Example:

私は昨夜快く眠った。