DISCLAIMER: PERFORM THIS MOD AT YOUR OWN RISK!
When you're trying to give your dolls different hands, you can normally buy them one pair at a time with most brands. With Smart Dolls ("SmD")...
Yeah, not really.
If you were to try to use Dollfie Dream ("DD") hands on a Smart Doll, the hands would be very loose on the wrist joint and can easily fall off under various circumstances. Sure, you can buy DD hands one pair (2160 JPY) at a time but they're pretty useless with a SmD. However, you're not forced to buy 4 pairs of hands at a time and spend 8900 JPY + 8% consumption tax if you're willing to try the following.
To the left is obvious. To the right is a USB flash drive.
Center: A soft cap for USB plugs.
Caps for USB plugs come in different thicknesses and hardness. I picked the softest one among the ones I have.
Disadvantage #1: You need two of these for the obvious reasons.
Disadvantage #2: The only skin tone pairing you'll be able to make (without something looking stupid) will be "Normal" for DD parts and "Milk" for SmD. "Tan" (DD) and "Tea" (SmD) might work but you would have to go to Akihabara Dollpoint to buy the "Tan" hand parts and I don't own a "Tea" colored SmD. I have no way of testing that color combination.
When removing or adding parts, please take the extra precaution of heating whatever parts you're handling with a blow dryer. Moonlight's intended hands slip on and off easily without any heat but fit onto the wrist joint without being loose. Depending on the USB cap, it may fit very tightly onto the wrist joint. Tugging on something tight poses a risk of something breaking, so it's always a good idea to heat the parts to make them soft and easier to remove. Something in the wrist breaking is my biggest concern. I can't replace these parts if they do break. T_T
Having said that, I recommend against using a hard plastic USB cap. Such a cap won't get soft by heating it with a blow dryer.
"Big Hands" Rock Fist.
Disadvantage #3: The soft USB cap will likely slide off the wrist joint and remain in the hand when you remove it from the wrist. You'll need to use tweezers to remove the cap from inside the hand.
When I was performing this trick, my biggest concern was when I saw how thin the wrist joint's peg is. While it's pretty sturdy in practice, I was still concerned about it anyway.
If you decide to try this trick on your Smart Dolls, please be careful. Use a blow dryer to heat up the parts you want to swap before attaching or removing them.