My first experience with this brand, Sailor Shikiori. Shikiori meaning four seasons. I read the stories that these are simply the old Jentl inks, rebranded and a lot more expensive. I never used those either. The bottle is small (20ml) and beautiful. Yonaga means long autumn night. The color represents an autumn night without the moon. The naming of the inks definitely reminds of Iroshizuku's style of naming their inks.
Yonaga is a very dark blue, with a slight hint of green. In very broad (oblique) nibs a bit of green sheen can be seen, but in normal pen sizes I didn't notice it. Being a dark blue, Yonaga can be used almost everywhere. Work notes, business correspondence, signing, personal notes, letters and writing.
The ink is very well behaved. Arguably the smoothest ink I have ever used. Quite wet, which makes drying time long (almost a minute) and there is some show-through even on quality paper. No feathering though and the shadowing is beautiful, clearly visible but never extreme or too much. Water resistance is low to moderate. Water will almost always require some rework of the page, but the text remains legible and won't be lost.
The color comes close to Iroshizuku's Shin Kai (Yonaga is just a bit more green). Imperial blue by Diamin is a lot more bright and saturated. Blue nuit by Herbin doesn't even come close.
All in all this is a very nice, but seriously overpriced ink.
