宵よいっぱり

noun

night owl; person who stays up late

Refers to a person who habitually stays up late at night. Often used in a self-deprecating or casual way.

• 私わたしは昔むかしから宵よいっぱりで、朝あさが弱よわい。

  I've always been a night owl and weak in the mornings.

noun or participle which takes 'suru'

staying up late; keeping late hours

The act of staying up late. Used with する to mean 'to stay up late'.