pleasantly; comfortably; agreeably
Describes doing something in a way that feels good physically or emotionally; often used with verbs like 眠る, 過ごす, 話す.
I spent a pleasant time soaking in the hot spring.
I slept comfortably last night.
I slept comfortably on the new futon.
He willingly took on the request.
Thank you for helping so readily.
He willingly took on the job for me.
I spent a pleasant time by the sea.
The children helped out cheerfully.
She spoke to me in a warm, easygoing way.
She readily agreed to the request.
快く is a more formal, written-style word for doing something willingly, while 気持ちよく is more casual and can also describe physical comfort.
嫌々 describes doing something reluctantly or unwillingly, the opposite attitude to acting 気持ちよく.
Standard kanji spelling for the adverbial form of 気持ちいい.
Alternate kanji spelling using 良 for よい; less common but still seen.
Adverbial form of 気持ちいい (気持ち + いい), literally 'feeling good'. The adverbialization follows the regular pattern of changing いい to よく.