"Temporarily boost your battle stats"
Boosters are items to help boost certain stats for a limited period of time. You can only have up to 4 active boosters at once. Each one lasts for 24 hours and you can hover your cursor over one of your equipped boosters to show how much time is left for it.
They come in 4 varieties across all 4 rarities. All kinds can be purchased in the shop. In addition, all except Legendary can be won from Arena battles. Epic & Legendary grade boosters can also be won from Epic Pachinko.
Ginseng Root
Common grants 100 Hardcore, Charm, & Know-How and costs 12 Kobans.
Rare grants 350 Hardcore, Charm, & Know-How and costs 30 Kobans.
Epic grants 1,225 Hardcore, Charm, & Know-How and costs 60 Kobans.
Legendary grants 6% Hardcore, Charm, & Know-How and costs 90 Kobans.
Jujubes
Common grants 400 Harmony and costs 12 Kobans.
Rare grants 1,400 Harmony and costs 30 Kobans.
Epic grants 4,900 Harmony and costs 60 Kobans.
Legendary grants 20% Harmony and costs 90 Kobans.
Chlorella
Common grants 1,200 Ego and costs 12 Kobans.
Rare grants 4,200 Ego and costs 30 Kobans.
Epic grants 14,700 Ego and costs 60 Kobans.
Legendary grants 10% Ego and costs 90 Kobans.
Cordyceps
Common grants 300 Damage and costs 12 Kobans.
Rare grants 1,050 Damage and costs 30 Kobans.
Epic grants 3,675 Damage and costs 60 Kobans
Legendary grants 10% Damage and costs 90 Kobans.