A contract is established. The Okiya pays for the Maiko's (considerable) training expenses. This includes a variety of expensive Kimono. The Geisha in the Okiya mentor the young Maiko.
When the Maiko becomes a Geisha she will make good money working in a teahouse (ochaya) where she will entertain men while they are drinking. This includes conversation, music, dancing and performances of traditional arts. She will also make money in public performances of Geisha arts.
Geisha will pay a large portion of their earnings back to the house. All this time she will live in the house with other Geisha, Maiko and house maids. The house mother (okā-san) is the boss in the matriarchal world of the Geisha. She strictly regulates the life of everyone in the Okiya.
When the Geisha's contract is up she's free to leave the house. She may decide to live outside the house and continue to work as a Geisha. At this time she will have more freedom to date. In many cases Geisha end up marrying wealthy customers.
In other cases, a Geisha is "adopted" by the house mother and continues to live in the house indefinitely. This is the path to becoming a house mother. Geisha live in a small community that values tradition. The daughters of Geisha often become Geisha themselves.
Okiya are old Japanese houses down the back streets in Geisha districts such as Gion, Pontochō, Miyagawachō, Kamishichiken and Shimabara in Kyoto.