Pikachu evolves to an anthropomorphic Pikachu.

Pikachu groaned as she levered herself up. She hurt all over. "Remind me not to investigate strange boxes with glowing rocks again."

"You okay, Pikachu?"

"Hurt. A lot." Pikachu felt a cup of something warm pressed into her hands and took it.

"This'll help," said Ash's voice. "It always helps me."

Lifting the cup to her lips, Pikachu drank gratefully and felt the warmth penetrating the pain. "Tastes horrible, but I... what?!"

Hands?

Pikachu slowly opened her eyes. Hands. Human style hands. Slender, furred except along the palm. Not paws. Hands.

"This is not good." Pikachu winced and looked down. "I'm a girl?"

"Were you before?" Ash blushed as he realized he hadn't known what gender his Pikachu was prior to this.

"Actually most pokemon have both male and female qualities - just that one is usually the dominant. We're also egglayers. That will not be fun." Pikachu mused.

"What now?"

Pikachu wanted to bash Ash and ask how she would know what happened next. She still felt a full charge so probably could use Thundershock and similar attacks. Ash was still taller than she was, but not by much. This was so strange. "We go to a pokecenter, I guess."

"Well, uhm, can you, err, cover up?" Ash passed his jacket to her.

Pikachu stared at it before remembering that humans had this weird nudity taboo. She had fur so it shouldn't apply but apparently Ash felt it did. Weird. "Okay, fine."