During his exploration in Kavirondo for a favourable place to set up a mission, Reverend James Jamieson Willis settled under a hickory tree. Among the Luo, the tree is known as Oseno, while the Luhya call it Omseno.
JJ Willis, as he was fondly referred to, liked the place probably due to the cold weather. A year later in 1906, he put up a church, and the same year, the place became known as Maseno.