よふ夜更yofuかしkashiよ夜yoふかしfukashi
1.
The act of remaining awake during the late hours of the night, often leading to feelings of tiredness the following day.
2.
The behavior of spending the night engaged in activities, such as reading or socializing, instead of sleeping.
3.
A tendency to prolong wakefulness into the early hours of the morning, frequently associated with a disrupted sleep schedule.
4.
The practice of staying awake late into the night, sometimes out of enjoyment or as a form of personal choice rather than necessity.
Example:
そんなに夜ふかしをするべきではない。