From Bulbapedia, the community-driven Pokémon encyclopedia.
Pokèmon with You is a campaign run by the The Pokémon Company to help fundraising and support of the 2011 Tohoku earthquake and tsunami disaster relief. It is partnered with Game Freak, Nintendo, and various other corporations.
After the Tohoku earthquake took place on March 11th, 2011, Pokèmon declared that they were going to help. While nobody from Pokèmon (or Nintendo for that matter) was directly affected, the repercussions of the disaster spread throughout the nation. Pokèmon immediately responded by delaying the opening of the international Pokèmon Global Link websites, and in May that they would also assist through the Pokèmon with You campaign.
Pokèmon with You has hosted several events to both fundraise and boost the morale of the citizens of Tohoku, and usually include an appearance by a person dressed in a Pikachu costume. Funraising events have included Pokèmon hosting tourism festivals as well as sponsored walks. Pokèmon with You has also attempted to lift the spirits of the citizens of Tohoku through Pikachu visiting several local schools.
In addition to fundrasing through events, Pokèmon with You also has a place on their website where those interested can donate to helping the victims of the disasters.
Pokèmon Centers have sold various merchandise and given part of their profits to support Pokèmon with You. The most notable merchandise was a series of buttons sold by Red Cross for $25 dollars from June 4th through August 31st. Around 50,000 buttons were sold.
Pokèmon Center Tohoku
Additionally, Pokèmon opened a new Pokèmon Center in the area affected by the disaster. On its grand opening, the line to enter the building was so long that people had to wait over five hours to enter.