This armored clothing gains +3 to your Armor Class.  You gain resistance to cold damage.

Heavily "Armed":  You gain four tentacles that stay hidden underneath your Yukata, wrapping around your body.  These arms act on your own volition, and can use them to make a single extra attack to either slap or grapple and enemy.  The attacks deal 1d6 Bludgeoning and 1d6 Cold Damage per hit and their speed is reduced by 5 feet per slap. Your tentacles have the reach property when used.  You may grapple a target that is large size and lower.  When grappling a target like this, you make a grapple check your DEX with advantage versus enemy STR with disadvantage.  Targets grappled this way may continue to make a save at the start of there turns.  This requires an action to do so.  

Slippery When Wet: Can use your reaction to take half damage from a source you can see.  You also gain the ability to fit into spaces that normally you could not.  You can excrete a slimy mucous over your body to aid in this process (Grease Spell at will).  When covered in mucous, you gain resistance to fire damage.  You can breathe underwater and have a swim speed equal to your movement speed.

Ink Jets:  You gain the ability to utilize ink based abilities for offensive/defensive capabilities.  You can cast the Darkness spell at will, which you may see through as normal.  You may also fire ink blobs out of your mouth as projectile based ranged attacks.  These blobs do 1d10 bludgeoning and may make four ranged spell attacks that act act like Eldritch Blast.  Similar to the Slippery When Wet ability, you may cast Grease at will to fire a stream of ink towards the ground which makes it difficult terrain for 1 minute. 

Cephalopod Magic:  When attuned to this Yukata, the following spells are added to your list of spells known.  You may cast each of these spells once without expending a spell slot or material components, after which you must complete a long rest before doing so again: Arms of Hadar, Ensnaring Strike (tentacles), Enlarge/Reduce, Hunger of Hadar, Shadow of Moil (tentacles)

• 2 minor detrimental properties:  While you are attuned to the artifact, your flaw is amplified in a way determined by the DM.  You deal 1d6 necrotic damage to any plant you touch that isn't a creature.
• 1 major detrimental property:  When you become attuned to the artifact, you gain a form of long-term madness.
• 1 minor beneficial property:  While attuned to the artifact, you gain a +1 bonus to AC.
• 1 major beneficial property:  you gain +2 to you Dexterity Modifier while wearing this armor.   

Made from tough but flexible leather, studded leather is reinforced with close-set rivets or spikes.

Notes: by a champion of Kamui, Many Armed Menace