you get it from cheryl when you guide her through eterna forest:').
Chat with our AI personalities
After saving mr fuji in Pokemon tower return to Pokemon tower with the itemfinder and stand in the spot where mr fuji once stood and use the itemfinder you should dig up a soothe bell.
give it a sooth bell {if you have one] hope this helps!!!
In salport city there is a woman looking at a picture in the Pokemon fanclub. Make sure the first Pokemon in your party has full happiness's. Then talk to her and she will give you the soothe bell.
the easyest way is to give it a sooth bell and keep riding up and down cycling rode. You could also enter contests and WIN with that Pokemon, give it a lot of vitimins, walk with it in amity square, feed it poffins, or the just basic way is to give it a sooth bell and just walk with it, that's the longest way though.
Get Golbat to love you (catching it with a luxury ball will help) then level it up once
Give a Soothe Bell it raises happiness.