shadow333

When pichu really likes you or loves you (this can be done by training it), it will evolve.

Note: Give it a Soothe Bell it will evolve quicker.

Broly 2000

You should level it up, or just make it happy in general. Then when it has two big hearts on it, level it up, and it should evolve.

Zitadul

Evolve by Friendship...
If you try to catch one pichu make sure you use a Luxury Ball it raise your closenest to each other.If you already have one pichu and his in a different Ball (other than Luxary Ball) have pichu hold Soothe Bell (you can get 1 at the Mansion from a maid) then level it up by battling trainers or battling wild Pokemon, just keep battling until it evolves.(it works better between 7am-5pm)

The fastest way evolving pichu to pikachu is get tons of vitamins and couple Rarecandys.(vitamins=HP Up, Carbos, Protein etc.)
Feed pichu tons of vitamins until he can't eat anymore (message will appear,"It won't have any effect") then level it up using rarecandys or battle it with wild pokemon.(less than 5 level up it will evolve)

GoodLuck.

If you have any question about anything about Pokemon e-mail me zitadul_2005@yahoo.com