Hey Yatagarasu!
Oops! Sorry for not answering your last message.
This was correct - symphatetic strings are common in indian instruments, but for example the biwa employs the same idea nicely, in addition to the shamisen.
Indeed. I believe when the shamisen arrived to Japan (either as the Chinese SanXian or Okinawan Sanshin), it was the taken up by the biwa players, who adapted the instrument to match their aesthetic tastes. Namely, the large plectrum, curved headpiece, and the buzzing sawari (which isn’t on either the SanXian or Sanshin). It’s suspected to have actually been inspired from the Indian sitar’s buzzing effect, called “jawari” (jawari…sawari… coincidence?)
It’s good, I mostly like it. Brings enjoyment to the beginner for a good while. Judging by the sales video, Kyle seems to be quite impressed by it. Can’t really discredit any of his comments.
I’m glad you mostly like it!
I still love playing with it. Any “beginner” level shamisen I’ve played before was never satisfying for me (specifically because of the use of thick, plastic skin). Thus, to finally have an affordably priced shamisen (considering the price of most shamisen) that’s resonant and clear almost blew my mind. Of course, knowing that every skin is different (and thus, the tone of every shamisen will be a bit different), I factored that fact into my evaluation.
With the shari koma, mine feels a bit hard, harsh, cold.
Hmm… what distance do you have the koma from the neo? And also another important factor, where are you playing the shamisen? I made sound isolation panels in the studio where I filmed it, and that might cut back sharp response (though I personally do prefer a sharper tone than a warm tone) than if it were played in a reverb-heavy room.
Kyle: Which strings are used on the videos? Mine I think has 1 nylon (san no ito - looks translucent and smooth) and 2 tetoron (? not quite as translucent, and no slippery smooth surface).
Mine are exactly the same. 
The resonant sound is the good part! Rich and satisfying, feels like a guitar as it should have been 
Yeah! the resonance is even more noticeable when it’s played side by side with a plastic skin shamisen. (which often sounds dull/muddy above position ‘10’)
Think I’ll add the sawari effect quite soon…
I stress, file slowly and test often. Unfortunately, I filed a little too far (perhaps 0.5mm, or less) and the string touched the ridge too much to get the optimal buzz. So, I put in a small piece of tape to lift it up. 
Kyle made at least 2 other videos, which may give you a better idea how it sounds, here’s Yasaburo Bushi (BTW that’s the colour of the sao for my shamisen as well):
Ooh!! Speaking of which, I recorded another song on the Beginner’s Shamisen for Karl! (We were talking about a certain song on Facebook) Here it is! One of my favorite old time folk songs, Maggie Walker Blues. (Also called “I’ve Always Been a Rambler” or “Roving Cowboy”)
Other entry level shamisen I’ve seen in online shops have often been at a significantly higher price.
Yeah, other online shops mark up the price considerably. Seeing how important it is to have truly affordable shamisen available, we’re barely selling above cost (just a bit to cover fees/costs). Fortunately, my partner in Japan also believes how necessary this is to help shamisen grow in the world, so he’s donating his time and energy to this cause. Unfortunately, it seems the Japanese shamisen world believes that price = quality, believing that if the price is low, people will think it’s crap and won’t want to buy it. (Yet ironically, the price some companies charge for crappy shamisen/bachi is shamefully high). I’ve tried to explain that low price = accessibility (to get new enthusiasts in the game), but it hasn’t seemed to register in their mindset. (and yet, they’re surprised why we’ve sold so many!)
Okay, my rant is over. 
Excellent reviews and comments, Yatagarasu! Bachi on!!!