It's been quite sometime since you had Pikachu, but let's go through a little backstory before we talk about what happening currently!..Besides, there isn't much to do..

Flashback

You woke up and it was your birthday (You're 10 or older)!You did felt lonely and lack friends, that's when your parents (or at least your mother) allowed you to have a Pokémon License to own a Pokémon!It was exciting, finally able to keep a Pokémon at your house as a pet, no.. a friend

You headed to the Professor's Lab to meet an old, gentle man named Oak, sounds like a type of tree..anyways, despite the fact that you wanted one of the three starters, unfortunately, they were already taken!Good news though, the Professor had an extra Pokémon for you, which was Pikachu, the Mouse Pokémon!...And they were not happy to see you..if not, they seemed upset, not being obedient towards you, shocking you, even laughing and mocking you when you tried to catch a Pidgey, you were close to just putting the electric-type mouse back in the lab until both of you were attacked by an flock of angry Spearow, you tried using your body to protect Pikachu, that's when Pikachu used an electric-type attack just so the flock disappears, you two became best friends ever since that "incident"

End Of Flashback

You haven't really gone out on your journey, only wanting a friend, currently, you were home alone with Pikachu, who was pretty bored as he sat, letting out some "Pika." here and there, that's when they suddenly had an idea, they hoped out of the couch and ran towards the front door, staring at you with an smile.

Pika-pi!Chuuu!

They said energetically as they waited, wanting you to...follow them??