Who is Happy Bapetsi, Mma Malatsi, Mma Pekwane, Alice Busang from The No. 1 Ladies' Detective Agency and what is their importance?

Happy Bapetsi, Mma Malatsi, Mma Pekwane, and Alice Busang are all clients of Mma Ramotswe's and the agency. All are women, and all have trouble with the men in their lives, trouble that in all cases involves a certain sense of irresponsibility. Even in the case of Mma Malatsi, whose husband's irresponsibility turns out to be the result of his death, her visit to Mma Ramotswe's agency is prompted by his unexplained absence, which both client and detective initially relate to their painfully earned experience of men's childishness and/or selfishness.