I was given a sample of this ink earlier in the year but it wasn't until I eventually swatched it on Tomoe River that I decided to grab a bottle; I've never seen an ink sheen quite like this one. As a Nagasawa Sailor-made exclusive, the ink isn't the cheapest to acquire from outside of Japan (and even within Japan there are restrictions on how many you can buy at a time). Before I continue, yes I am aware of the spelling error throughout the written review. I thought Kitanozoka sounded more Greek than Japanese but I didn't do my research enough and instead relied on an incorrect spelling that I read online! Oops.
The ink, like most Sailors, is very nicely lubricated and highly saturated. As a dark saturated ink, however, its shading, while there, is somewhat subtle. The blue-black leans towards the purple rather than the green side of blue and its dry time, while not as bad as some inks (and even some Sailor inks) is on-par with most Sailor inks in that it's far from a quick dryer at over 30 seconds on Rhoda paper. Where it gets interesting is with the sheen!
Never have I seen an ink that sheens two different colours. Blues sheen Red or copper, Purples and reds green or gold and some other sheens silver. Kobe #38 sheens both a matte burgundy red on it's surface, and where the ink pools a nice shiny green. Two sheens for one ink! It does need Tomoe River and a wet pen to bring out the green but it is there. The Chromatography features a grey line where the ink was put onto the paper, some purple, some blue-leaning black and finally some cerulean blue. I imagine it gets the green sheen from the purple component if the ink.
The best comparison that I have to Kobe #38 is Rober Oster Blue Night. It won't sheen the same but the hue and shading are very similar. Iroshizuku Shin-Kai is a little too grey, and Bungubox 4B is too green leaning while both Private Reserve Midnight Blues and Noodler's Bad Belted Kingfisher are both bluer (with less black than Kobe #38) and have even less shading.
Surprisingly, and comparably to Bungubox Valentines Choco Brown, the ink fair pretty well in the wet leaving behind a grey line after the blue is washed (and slightly rubbed) away.
This ink, thanks to the sheen is in my top two blue-blacks along with Bungubox 4B. While I would prefer more shading, I love the hue and the sheen is just something special. Sailor inks are my favourite ink-brand but apart from the internationally sold inks they come with a price tag and with this one, I think it's worth it. It's priced less than Bungubox and Iroshizuku and I definitely prefer it to the latter. If you have a wet nib and Tomoe River I can't recommend this enough, but if you don't, I still think it's still a solid blue-black that deserves consideration.
I bought this ink from cool-japan on Ebay. I was not compensated for this review and everything here is my own honest opinion. There are no affiliate links.