Wanting to increase your abilities in ranged combat and not just hand to hand to hand has lead you to teach yourself the way of the Yo-Yo. You are able to push your ki into the string and end of the Yo-Yo and manipulate it as if it was your own body. While not a common practice in the history of monks, it is still a very useful technique, and those who have mastered it have become very powerful warriors.

Yo-Yo Technique

Whenever attacking with your Yo-Yo, you can choose to activate this ability to wrap up and enemy in the Yo-Yo string. This can also be used outside of combat to form the string into whatever you like within the limits of its length.

• You can spend a Ki Point to make a second grapple check against a creature you have grappled with your yo-yo. If they fail, they are restrained until they break out. 
• The yo-yo's reach increases at 7th, 13th, and 17th level. 

Spirit Yo-Yo

You can expend any amount of ki points to create an exact copy of your Yo-Yo when attacking. You roll to hit for each Yo-Yo made this way and the Yo-Yos deal act the exact same way as whatever is being copied. The number of yo-yos made depends on the number of Ki points expended. This attack can only target one person. This attack duplicates any effects the yo-yo has on it, including poisons

Ki Explosion

You can expend 4 ki points to make an explosion on impact within a 10-foot radius around said point of impact. Must be stated before making an attack, on a successful attack the target and anyone within a ten ft. radius takes 3d6 bludgeoning damage except for the target who was hit directly who takes 5d6 bludgeoning damage. They are all also pushed back 15 ft and must succeed on a dex saving throw or be knocked prone.

Human yo-yo

At 17th level, When you wrap an enemy up with the Yo-Yo technique, you can spend 4 ki points to wrap the enemy up with a giant magical yo-yo end, and crushed down to a usable size. This doesn't kill them. However they are now able to be attacked with, this magic yo-yo deals 4d10 +10 and can be duplicated by the Spirit Yo-Yo technique. When attacking with the Yo-Yo, whoever is inside takes 2d8 bludgeoning damage with each successful attack (This damage is increased with the use of the Spirit Yo-Yo technique). 

• This attack lasts up to a minute of concentration 
• The creature being Yo-Yoed can break free by making a DC 25 strength check