This is a guide to leveling your Flower Knights. Unlike in some card games like Kantai Collection, your girls level by feeding them by other cards. Depending on what your giving to them will not only increase their level but also unlock their accessory slots as well as increasing their skill level.
Increasing their level boost their HP, Attack and Defense.
How to increase level
Technically as said above feeding them by almost anything will increase their exp which eventually levels them up. However as their levels increase, the cost (gold) begins to go higher per session thus it is important to search for fairies.
How to acquire fairies
Fairies can be gain in 4 ways; 1st from commissions; 2nd from Normal Gacha, 3rd from Daily Missions and the last from search. The 1st and 2nd will only give you Tier 1 Fairies (5-year old Fairies) that yields small exp but good when your flower knights are still at low level. the 3rd requires you to be in a specific day of the week but depending on the difficulty will give you Tier 2 to Tier 3 Fairies and the 4th has a variable chance to give high rarity fairies.
How Increase Skill Level/Unlock Accessory Slot
You'll simply need a replica of the flower knight to do this. This is very common to high rarity flower knights as not only increases their skill level also unlocks their accessory slot.
For ★2 to ★3 as well as some ★4 rarity flower knights, it is possible to increase skill level by finding the other flower knight who also posses the same skill as theirs. The chances of increasing skill level is random.
In events, the event Flower Knight can quickly unlocking their Accessory as well as increasing their Skill Level by giving them the a flower.