You can earn the emblem and emblem shards seen above by battling AI enemies in Jurojin: Immortal Ninja. In addition to the other items they drop when defeated, you also receive these emblems based on their difficulty level. The harder the opponent, the better the reward!
Each time you defeat a tier one ninja minion they drop one of the emblem shards on the far left. Earn two of these halves and you can redeem one full tier one black emblem to enter tier two and face off against the second ninja foe. Each time you beat that opponent you get a green emblem shard, which means it'll take two more wins before you can combine them for a full green emblem and challenge a tier three Ninja Boss! A victory against him guarantees you a rare scroll that has a higher chance to contain rare rewards!
The purple emblem on the right has a chance to drop from any of the NPC enemies, with drop odds that increase with the tier of the enemy. This epic emblem can then be redeemed to battle a special boss who drops an epic scroll case!