One way to increase the happiness/friendship level of your Pokémon is by giving them a massage. To do this you’ll need to visit the Pokémon Groomer, who’s located in the western section of Mauville City’s interior.
The Pokémon Groomer can give a massage to one of your Pokémon each day for free, boosting their happiness level.
Location
Mauville City has various shops and multiple floors. You’ll find the Groomer in the northwesternmost corner of the city’s interior, and you can spot her stall by looking for a distinctive statue of a massage chair as you stroll down the hallway.
From Mauville City’s Pokémon Center, make your way west and head through the archway here – this should take you back into the city’s interior.
Now that you’re in the city’s interior, head north up the hallway.
You’ll be looking for a statue of a massage chair to signify the Pokémon Groomer’s stall (it’s the third stall on the right as you head north).
Once you find the Pokémon Groomer’s stall, approach her and she’ll offer to give a massage to the first Pokémon in your party.
Note that you can only get one massage per day.
NPC Mechanics
The Pokémon Groomer can give one of your Pokémon a massage each day, boosting its happiness. This can be particularly useful for evolving Pokémon that rely on happiness to evolve or boosting the base power of the move Return.
But before you talk to the Pokémon Groomer, make sure the Pokémon you want massaged is leading your party in the first slot.
You won’t get to choose which Pokémon gets a massage, as she will only offer to massage the Pokémon leading your party.
After the massage, the Pokémon Groomer will communicate to you how your Pokémon feels. Remember that the Pokémon Groomer can only give one massage per day, so choose your Pokémon wisely!
