Christian Richard created Toki Pona after some years of activity in the Esperanto movement, so the two languages spring out of a shared history. This is also why people miss the point when they complain on these HN threads about Toki Pona apparently not being a full, usable language: there was already Esperanto for that, Toki Pona was intentionally created as an experiment, a sort of conlang Oulipo.