Where does “プラン” come from?

プラン (Japanese) comes from English plan, from French plan, from French plain, from Old French plain, from Latin plēnus, from Proto-Italic plēnos, from Proto-Indo-European pl̥h₁nós, from Proto-Indo-European pleh₁- — to fill.

プラン (Japanese): plan, a set of intended actions; plan, diagram,...