From Bulbanews, your community Pokémon newspaper.
Available starting March 18
To celebrate Easter, six different Pokémon Eggs will be available at Pokémon Centers and Pokémon Stores in Japan from March 18 to April 9, 2017 for Pokémon Sun and Moon.
Mareanie, Oranguru, Passimian, Turtonator, Drampa, and Goomy will be available in the Eggs. Only one of these Eggs can be obtained per day.
From March 18 onward, if players show a Pokémon hatched from one of these gift Eggs to an employee at a Pokémon Center store, they can receive a Pokémon Training Guide (育て方ガイド). These guides are limited to one per person, and are only available until supplies run out.