The official Pokémon website has announced that players of Pokémon Ultra Sun, Pokémon Ultra Moon, Pokémon Sun and Pokémon Moon will be able to get a Mystery Gift containing an Enigma Berry, a Micle Berry, a Custap Berry, a Jaboca Berry and a Rowap Berry. This Berry distribution runs from January 7th, 2019 at 8:00 p.m. PST until September 2nd, 2019 at 4:59 p.m. PST.

Get Rare Berries

Don’t miss your chance to obtain these elusive treats that will boost your Pokémon’s performance.

Starting early January of 2019, Pokémon fans will be able to take part in a Berry exciting event (see what we did there?). Players of Pokémon Ultra Sun, Pokémon Ultra Moon, Pokémon Sun, and Pokémon Moon will have the opportunity to get a Mystery Gift containing a selection of special Berries that have previously been unavailable in the games. The Mystery Gift contains an Enigma Berry, a Micle Berry, a Custap Berry, a Jaboca Berry, and a Rowap Berry.

Each of these rare Berries has useful effects when held by a Pokémon, but you may not want to use any right away. By traveling to Poké Pelago in your game, you can plant the Berries to grow more of them. With proper maintenance, your supply of these handy items will never run dry.

Competitive players will be pleased to learn that these Berries can be used in Pokémon Global Link Rating Battles and Online Competitions (unless the regulations state otherwise). They can also be used for the 2019 Video Game Championship Series from the Moon Series onward.

This Berry distribution runs from January 7, 2019 (8:00 p.m. PST), to September 2, 2019 (4:59 p.m. PST), so don't miss out on adding these valuable items to your game!

To get your Berries via Nintendo Network:

1. Select Mystery Gift on the main menu.
2. Select Receive Gift.
3. Select Get via Internet, then Yes, and then Yes again to connect to the internet.
4. Watch as you receive your Berries.
5. Speak to the delivery person in any Pokémon Center to add the Berries to your inventory.
6. Be sure to save your game!

Source: https://www.pokemon.com/us/pokemon-news/get-rare-berries/