As a Pokémon expert, I can tell you that evolving a Togepi into Togekiss requires a specific item known as the Sinnoh Stone. Here's how you do it:

1. Obtain a Sinnoh Stone: This is a special evolutionary stone that was introduced in the Sinnoh region of the Pokémon world.
2. Give the Sinnoh Stone to Togepi: During a battle, when Togepi is on your team, you can use the stone on it.
3. Togepi Evolves: If the conditions are met, Togepi will evolve into Togekiss right after you use the stone.

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You can evolve your Togepi into Togetic by leveling it up while it has max happiness. You can then evolve it into Togekiss by using a Shiny Stone.read more >>