Change your preferences here.
Berry Juice restores the HP of the holder by 20 hit points when the holder is at 50% HP or less.
Ordinarily, 20 HP healing is not a very big deal, and in just about all cases is outclassed by Sitrus Berry, which is a poor item in most tiers regardless. The one exception to this general rule is Little Cup, where most Pokemon have around 20 HP and so this item is able to bring them back to full health even if they are on the verge of death, and cannot be removed by Bug Bite or Pluck, unlike Oran Berry. In fact, it's so good that it was banned for being overpowered, so cannot be used there regardless. Oh well.
Black City - buy from School Kid Shane for 1500 Poké Dollars.
Royal Unova - defeat all trainers on board on Tuesday.