I think the biggest problem is the instrument, If you are good at carpentry you can try making your own.
Or find out if there is local Japanese community who has the instrument imported into the US.
Or try to ship in one from Japan, but the size of the instrument meant expensive shipping fees.
the instrument is about 5 - 6 feet in length.
And you might need to purchase spare strings when buying together with the picks.
Here is a making video. www.youtube.com/watch?v=l5SS1B…
If there is a community or even teacher you can learn at the local club house or something,
most of the accessories will be provided.
This is a video I found for the Yamada Ryu koto club that uses the point picks.www.youtube.com/watch?v=r0-Qra…
This is the guzheng school team my sister coached for national competition 11 years ago.www.youtube.com/watch?v=bK-N_g…
This is my sister performing our dialect group classics, that is in F-major.www.youtube.com/watch?v=plUbuW…
Japanese Koto uses the Hira Joshi that is minor scale with MI and LA being flat,
Chinese guzheng uses mainly the Nogi Joshi (in Japanese koto system) that is pentatonic scale
Korean Kayageum is the Korean variant of Koto/ Guzheng.
(the kayageum is close to the Chinese zither but has bridges, and played without picks)
Guqin (zither) is the most ancient form that lacks bridges and the tones is pressed with the left hands and a lot of sliding tones.www.youtube.com/watch?v=6sVIV2…
This is the 3 variants side by side.
(Jasmine, Bellflower - Chinese Guzheng pieces)
(Sakura Sakura - Japanese Koto piece)
(Arirang - Korean Kayageum piece)www.youtube.com/watch?v=3B8xS7…
Japanese Koto are usually 13 strings, while the Chinese 21 strings guzheng is called "nijugen" or "20-string", the 21 strings variant does exists in Japan.
the "25-strings koto" is called "Se" in Chinese which isn't as common since most of the pieces are written for 21 strings.
13 strings Koto playing Sakura Sakura with the rectangular picks that is the more common in Japanese koto.www.youtube.com/watch?v=SYians…
17 strings Koto playing Senbonzakurawww.youtube.com/watch?v=dn7Xev…
21 string Guzheng playing Senbonzakurawww.youtube.com/watch?v=g293pF…
25 strings kotowww.youtube.com/watch?v=JDTp_Y…
You can make the picks from materials like acrylic, polypropylene (plastic tubs), and even polystyrene (though polystyrene isn't too durable and tend to chip)
These are guzheng picks I made, hand crafted with sandpaper and flower pruning scissors for trimming the pieces into rough shapes, so no power tools needed.
the first picture with the black turtle shell set is actually a set made by an artisan friend from Beijing
These are Beijing styled picks that is sharp teardrop points, that is close to the Yamada Ryu picks in Japan
Japanese koto picks uses a leather loop or rubber ring, which the Chinese guzheng picks uses bandage tape for sticking the picks to finger,
so if you are making your picks
just get a 24mm wide bandage tape and slice it into 3 slices of roughly 8mm strips which will be sufficient,
duct tape is sticky but the perspiration will be trapped making it slippery after playing a while.