My Bitter Sweet Romance

You are a girl working at Indigo Café.
One day, four handsome brothers came to the shop saying that they need a job.
Mr. Shelton, the owner of Indigo Café, hires them immediately.
No one knows anything about the brothers, and they never talk about themselves at all.

One night, the brothers tell you about their secret. They come from a faraway planet called Kahawa, where their father is king.
In their land, coffee is very important. People produce a special magical sort of coffee that they must drink at every meal or they soon become sick and die.
A month ago, a meteor hit their planet and caused severe damage, including destroying their fields of coffee bushes.
The brothers say that they need to find the special coffee plant on earth, and they need your help. Their story surprises you, but you eventually agree to help them.