Mount Hiei is a big mountain in Japan that is very important to a religion called Buddhism. People who follow Buddhism believe in something called enlightenment, which is like becoming very wise and understanding things very deeply.
In Buddhism, there are different groups called sects that have different beliefs and ways of doing things. One of these sects is called Tendai and it started on Mount Hiei.
Tendai Buddhists believe that Mount Hiei is a very special place where they can get closer to enlightenment. In order to do this, they have to climb up the mountain and stay in a special place called a temple. The temple is kind of like a big house where the monks who follow Tendai Buddhism live and study.
The monks who live on Mount Hiei follow a very strict set of rules and routines. They wake up very early every day and spend most of their time studying and meditating. Meditating is like sitting very still and quiet and thinking about things deeply.
In addition to climbing the mountain and staying in the temple, Tendai Buddhists also believe that they can get closer to enlightenment by doing good things for others. This can include helping people who are sick, feeding hungry people, and just being kind to others.
Overall, Mount Hiei is a very important place for Tendai Buddhists because it is where their religion started and where they believe they can get closer to enlightenment.