Multiple Stories:
MAIN: Orphaned and poor guy has to guide the new worker who is a rich guy trying to learn about society.
2nd Story: (Fave) The butler of rich guy and the chef/head of the restaurant have a thing.
3rd: Childhood friends. One is introverted and doesn't leave the house. Other is extroverted. Reunited after years of not seeing each other.
Koi no Hajime